Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus): COSEWIC assessment and status report 2018

Official title: COSEWIC Assessment and Status Report on the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) Appalachian population, Carolinian population in Canada 2018

Committee on the Status of Endangered Wildlife in Canada (COSEWIC)
Endangered 2018

COSEWIC assessment summary

Assessment summary – April 2018

Common name: Allegheny Mountain Dusky Salamander - Appalachian population

Scientific name: Desmognathus ochrophaeus

Status: Endangered

Reason for designation: This salamander with aquatic larvae inhabits forested brooks, cascades, springs, and seeps, where there is abundant cover in the form of crevices between stones, logs, or leaf litter. Its entire Canadian distribution is confined to a small area at Covey Hill, Québec, and is isolated from other populations in Canada and in the United States. Its small range makes this salamander highly susceptible to environmental fluctuations and chance events, and effects of various human activities. All occupied streams emanate from a single water source and are thus vulnerable to any activities or events that could lead to drying of habitats or contamination of the water source. Within the past decade, increased survey efforts have allowed better delineation of occupied areas and clarified threats, but substantial threats remain, and the risk to the population has increased due to increasing demand for water.

Occurrence: Quebec

Status history: The species was considered a single unit and designated Special Concern in April 1998. Status re-examined and designated Threatened in November 2001. Split into two populations in April 2007. The Great Lakes / St. Lawrence population was designated Threatened in April 2007. Population name changed to Appalachian population in April 2018; status re-examined and designated Endangered.

Assessment summary – April 2018

Common name: Allegheny Mountain Dusky Salamander - Carolinian population

Scientific name: Desmognathus ochrophaeus

Status: Endangered

Reason for designation: This salamander with aquatic larvae inhabits forested brooks, cascades, springs, and seeps, where there is abundant cover in the form of crevices between stones, logs, or leaf litter. Its entire Canadian distribution is confined to two streams within a small area of Niagara Gorge, Ontario, and is isolated from other populations in Canada and in the United States. Increased survey effort within the past decade has expanded the known area of occupancy from one to two streams. However, the small range and population size, probably fewer than 100 adults, makes this salamander highly susceptible to environmental fluctuations and chance events, and effects of human activities. The population would be lost if the groundwater flow or water quality in the two streams would become compromised by human activities or effects of climate change.

Occurrence: Ontario

Status history: The species was considered a single unit and designated Special Concern in April 1998 . Split into two populations in April 2007. The Carolinian population was designated Endangered in April 2007. Status re-examined and confirmed in April 2018.

COSEWIC executive summary

Allegheny Mountain Dusky Salamander - Appalachian and Carolinian populations
Desmognathus ochrophaeus

Wildlife species description and significance

Allegheny Mountain Dusky Salamander is a member of the lungless salamanders of the family Plethodontidae. Adults measure between 70 and 100 mm in total length and have a light mid-dorsal stripe that extends from the head to the tail. The dorsal stripe is straight-edged and flanked by very dark pigments; it often has a row of chevron-shaped dark spots down the middle.

Distribution

Allegheny Mountain Dusky Salamander is found throughout the Appalachian Mountain system of eastern North America. In Canada, its entire known distribution consists of two isolated populations near the U.S. border, one in Québec and the other in Ontario. A single historical record for the species in New Brunswick appears to be attributable to a misidentification.

The species was first discovered in Québec in 1988, where it occupies several streams and seeps on the north side of Covey Hill, with an extent of occurrence of 56 km². A second population was discovered in Ontario in 1989, although it was not recognized as Allegheny Mountain Dusky Salamander until 2004. Surveys carried out in 2010 resulted in the discovery of an additional locality for the species in this area, at a distance of over 350 m from the first locality. The Ontario population now includes two isolated streams in the Niagara Gorge with an extent of occurrence of only 4 km².

Habitat

Allegheny Mountain Dusky Salamander lives near small, slow-flowing streams, springs, seeps, wet rocky outcrops, and seepage areas with cold, well-oxygenated water in forested habitats at high elevations. The salamanders are typically beneath cover objects (stones, woody debris, moss, leaf litter) or in moist underground retreats near water. These habitats help them avoid predation and dehydration and provide shelter for resting, foraging, nesting, and larval development. Hibernation takes place in subterranean refugia with a constant supply of water.

Biology

The life cycle is complex and, unlike in many other plethodontid salamanders, includes an aquatic larval stage. The duration of the larval stage ranges from a few days to several months depending on moisture, temperature and food availability, and the larvae metamorphose when they reach a snout-vent length (SVL) of 10 – 18 mm. Sexual maturity is usually attained around the third or fourth year of life, when males and females reach a total length of 70 mm (37 mm SVL) and 73 mm (30 mm SVL), respectively. Females lay 8 – 24 eggs and remain with them through hatching, which occurs in fall and spring. Survivorship is high in early and middle life stages. Individuals have an average life span of 7 years but can live as long as 15 years. The generation time is presumed to be approximately 5 years.

Exchange of respiratory gases in adults takes place through the skin, and as a result the salamanders are very vulnerable to dehydration. This constraint imposes long periods of inactivity during dry periods, when the salamanders remain in moist retreats. The species is a generalist feeder that uses a sit-and-wait (ambush) mode of predation and can survive without food for long periods. Predators include carabid beetles, crayfish, snakes, small mammals, and birds. Individual salamanders occupy a small home range (less than 1 m²) from May – September but if displaced have been documented to home over distances of up to 30 m. They may move underground toward springs to forage or reproduce and to avoid predation or competition. The salamanders typically move along the stream corridor in an upstream direction, always remaining within reach of wet retreat sites.

Population size and trends

Despite the major efforts devoted to searching for dusky salamanders in Canada, the distribution of Allegheny Mountain Dusky Salamander remains extremely restricted, and the small populations are vulnerable to various anthropogenic threats and stochastic environmental events. The two Canadian populations are completely isolated from each other, and there is no possibility of exchange of individuals with U.S. populations. While both populations are very small (probably no larger than 1000 and 100 mature individuals in the Appalachian and Carolinian populations, respectively), there are no robust population estimates, and population trends cannot be determined from the available data.

Threats and limiting factors

Activities that could compromise the water supply and water quality in the habitat of Allegheny Mountain Dusky Salamander represent the most significant threats to the species in Canada. Lowering of the groundwater table and alteration of the streams supplying water to the occupied streams have the potential to destroy habitat and hinder the movement and continued existence of the salamanders. Contamination of groundwater and surface water by effluents from agricultural or silvicultural operations, runoff from urbanized or industrial areas, and/or air pollutants can reduce water quality. At the Niagara Gorge, landslides and mudslides could potentially reduce or eliminate the species’ habitat. Other threats include logging and urban development, which can have a major impact on moisture and temperature conditions and increasing sedimentation and siltation in streams, invasive species such as European Common Reed, and climate change, particularly droughts and their cumulative effect on the water table.

The species’ cutaneous respiration, limited dispersal capacity, and specialized environmental needs, along with its subjection to predation and competition, are limiting factors that contribute to the isolation of Canadian populations and to the species’ vulnerability.

Protection, status, and ranks

Allegheny Mountain Dusky Salamander, Great Lakes / St. Lawrence population (now termed Appalachian population), was listed as Threatened in Schedule 1 of the Species at Risk Act (SARA) in 2009. The Carolinian population was listed as Endangered in Schedule 1 of SARA in 2009. In Québec, the species was listed as threatened under the Québec Act respecting threatened or vulnerable species (CQLR, c. E-12.01) in 2009, and it is protected under the Québec Act respecting the conservation and development of wildlife (CQLR, c. C-61.1). In Ontario, the species is listed as Endangered under the provincial Endangered Species Act, 2007 (S.O. 2007, c. 6). Approximately 2% of the area of occupancy of the Allegheny Mountain Dusky Salamander is located on protected land. The remaining 98% is on private land.

Technical summary 1 - Appalachian population

Scientific name: Desmognathus ochrophaeus

English name: Allegheny Mountain Dusky Salamander, Appalachian population

French name: Salamandre sombre des montagnes, population des Appalaches

Range of occurrence in Canada: Québec

Demographic information

Generation time (usually average age of parents in the population): indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used.:

~5 years

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

Projected decrease based on threats from various sources

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]:

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations]:

Unknown

[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations]:

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future:

Unknown

Are the causes of the decline a) clearly reversible and b) understood and c) ceased?

Not clearly reversible (a),
partially understood (b),
not ceased (c)

Are there extreme fluctuations in number of mature individuals?

Unknown

Extent and occupancy information

Estimated extent of occurrence (EOO):

56 km²

Index of area of occupancy (IAO) (Always report 2x2 grid value):

56 km²

Is the population “severely fragmented,” i.e. is >50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?:

(a) No
(b) No

Number of “locations”^* (use plausible range to reflect uncertainty if appropriate):

1 location, based on a single source of groundwater for the occupied habitat, which could be contaminated or disrupted by a single threatening event

Is there an [observed, inferred, or projected] decline in extent of occurrence?

No

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

No, but possible

Is there an [observed, inferred, or projected] decline in number of subpopulations?

No

Is there an [observed, inferred, or projected] decline in number of “locations”*?

No

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Projected decline based on threats

Are there extreme fluctuations in number of subpopulations?

Unknown, but not apparent

Are there extreme fluctuations in number of “locations”?

No

Are there extreme fluctuations in extent of occurrence?

No

Are there extreme fluctuations in index of area of occupancy?

No

^* See Definitions and Abbreviations on COSEWIC website and International Union for Conservation of Nature (IUCN) (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Subpopulations (give plausible ranges) total: N Mature Individuals unknown but probably around 1,000

Quantitative analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years]: Not done due to insufficient data

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Was a threats calculator completed for this species?

Yes, on 18 July 2017

In perceived order of importance, threats are: (i) dams and water management (Natural system modifications), (ii) logging and wood harvesting (Biological resource use), and (iii) agricultural and forestry effluents (Pollution).

What additional limiting factors are relevant?

Specific habitat requirements and dependency on very moist habitats; small population size, increasing vulnerability to threats and stochastic environmental fluctuations

Rescue effect (immigration from outside Canada)

Status of outside population(s) most likely to provide immigrants to Canada?:

The closest New York population is isolated from the Canadian population by distance, and immigration is extremely unlikely.

Is immigration known or possible?

No, the population is isolated from the closest U.S. population (see Population Spatial Structure and Variability and Rescue Effect)

Would immigrants be adapted to survive in Canada?

Yes, possibly

Is there sufficient habitat for immigrants in Canada?

No

Are conditions deteriorating in Canada?⁺

Unknown

Are conditions for the source population deteriorating?⁺

Unknown

Is the Canadian population considered to be a sink?⁺

No

Is rescue from outside populations likely?

No

⁺ See Table 3 (Guidelines for modifying status assessment based on rescue effect).

Data-sensitive species

Is this a data sensitive species? No

Status history

COSEWIC: The species was considered a single unit and designated Special Concern in April 1998. Status re-examined and designated Threatened in November 2001. Split into two populations in April 2007. The Great Lakes / St. Lawrence population was designated Threatened in April 2007. Population name changed to Appalachian population in April 2018; status re-examined and designated Endangered.

Additional Sources of Information: Recovery Strategy for the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus), Great Lakes/St. Lawrence Population, in Canada (Environment Canada 2014).

Status and reasons for designation:

Status: Endangered

Alpha-numeric codes: B1ab(iii,v)+2ab(iii,v)

Reasons for designation: This salamander with aquatic larvae inhabits forested brooks, cascades, springs, and seeps, where there is abundant cover in the form of crevices between stones, logs, or leaf litter. Its entire Canadian distribution is confined to a small area at Covey Hill, Québec, and is isolated from other populations in Canada and in the United States. Its small range makes this salamander highly susceptible to environmental fluctuations and chance events, and effects of various human activities. All occupied streams emanate from a single water source and are thus vulnerable to any activities or events that could lead to drying of habitats or contamination of the water source. Within the past decade, increased survey efforts have allowed better delineation of occupied areas and clarified threats, but substantial threats remain, and the risk to the population has increased due to increasing demand for water.

Applicability of criteria

Criterion A (Decline in Total Number of Mature Individuals): Not applicable. Although there is a projected decline in the number of adults based on threats, its magnitude is unknown.

Criterion B (Small Distribution Range and Decline or Fluctuation): Meets Endangered, B1ab(iii,v)+2ab(iii,v), because both EOO and IAO are below threshold values, there is 1 location, and there is a projected decline in habitat quality and numbers of mature individuals based on threats.

Criterion C (Small and Declining Number of Mature Individuals): Not applicable. Although the population size is below threshold for Endangered and there is a continuous decline based on threats, subpopulation structure and subpopulation sizes are unknown.

Criterion D: Not applicable. Meets Threatened, D1, because the population size is suspected to be below 1000 adults, but no robust estimates are available. Meets Threatened, D2, because the small population is prone to human activities and/or stochastic events, which over a short period could lead to the population to become critically endangered should these activities/events affect the ground water that feeds all occupied streams.

Criterion E (Quantitative Analysis): Not done due to insufficient data

Technical summary 2 - Carolinian population

Scientific name: Desmognathus ochrophaeus

English name: Allegheny Mountain Dusky Salamander, Carolinian population

French name:Salamandre sombre des montagnes, Population carolinienne

Demographic information

Generation time (usually average age of parents in the population): indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used.: ~5 yearsIs there an [observed, inferred, or projected] continuing decline in number of mature individuals? Yes, inferred and projectedEstimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]: Unknown[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations]: Unknown[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations]: Unknown [possible 50% reduction in mature salamanders over the next 10 years if the individuals in the location affected by an accidental grout spill in 2016 fail to reproduce.][Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future: UnknownAre the causes of the decline a) clearly reversible and b) understood and c) ceased? (a) Unknown
(b) Yes
(c) YesAre there extreme fluctuations in number of mature individuals? Unknown

Extent and occupancy information

Estimated extent of occurrence (EOO):4 km²Index of area of occupancy (IAO) (Always report 2x2 grid value):4 km_² (The actual area of occupancy is 0.4 km²)Is the population “severely fragmented,” i.e. is >50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?: (a) No
(b) Possibly. The streams occupied by the species are separated by over 350 m of dry habitat inhospitable to salamander movements.Number of “locations”^* (use plausible range to reflect uncertainty if appropriate):2 locations, based on occupancy in two streams, each with a different ground water source that could be contaminated or disrupted by a single threatening eventIs there an [observed, inferred, or projected] decline in extent of occurrence?No (the known extent of occurrence increased with the discovery of a new locality in 2010)Is there an [observed, inferred, or projected] decline in index of area of occupancy?No, but a decline is possible particularly in light of an accidental grout spill that occurred in 2016Is there an [observed, inferred, or projected] decline in number of subpopulations?NoIs there an [observed, inferred, or projected] decline in number of “locations”*? Unknown [A second location was identified in 2010, but the first one was contaminated by a grout spill in 2016.]Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat? Yes, observed and inferred decline in habitat quality, and possibly in the area and extent of habitat.Are there extreme fluctuations in number of subpopulations? NoAre there extreme fluctuations in number of “locations”? NoAre there extreme fluctuations in extent of occurrence? NoAre there extreme fluctuations in index of area of occupancy? No

^* See Definitions and Abbreviations on COSEWIC website and International Union for Conservation of Nature (IUCN) (Feb 2014) for more information on this term.

Number of mature individuals (in each subpopulation)

Subpopulations (give plausible ranges) total: N Mature Individuals unknown but most likely < 100; preliminary estimate suggests ~33 adults

Quantitative analysis

Probability of extinction in the wild is at least [20% within 20 years or 5 generations, or 10% within 100 years]: Not done due to insufficient data

Threats (actual or imminent, to populations or habitats, from highest impact to least)

Was a threats calculator completed for this species?

Yes, on 18 July 2017

In perceived order of importance, threats are: (i) dams and water management and habitat modification by invasive Common Reed (Natural system modifications), (ii) industrial effluents and other sources of contamination (Pollution), and (iii) landslides (Geological events).

What additional limiting factors are relevant?

Specific habitat requirements and dependency on very moist habitats; small population size, increasing vulnerability to threats and stochastic environmental fluctuations

Rescue effect (immigration from outside Canada)

Status of outside population(s) most likely to provide immigrants to Canada?: The species has an extensive range in the United States.
The closest population in New York state is secure (S5)Is immigration known or possible? No, the population is isolated from the closest U.S. populations by the Niagara River and geographic distance (see Population Spatial Structure and Variability and Rescue Effect)Would immigrants be adapted to survive in Canada? Yes, possiblyIs there sufficient habitat for immigrants in Canada?NoAre conditions deteriorating in Canada?⁺Yes, one of the two locations was accidentally contaminated by a grout spill.Are conditions for the source population deteriorating?⁺ UnknownIs the Canadian population considered to be a sink?⁺NoIs rescue from outside populations likely?No

⁺ See Table 3 (Guidelines for modifying status assessment based on rescue effect).

Data-sensitive species

Is this a data sensitive species? Yes, following data sensitive designation by the Province of Ontario

Status history

COSEWIC: The species was considered a single unit and designated Special Concern in April 1998. Split into two populations in April 2007. The Carolinian population was designated Endangered in April 2007. Status re-examined and confirmed in April 2018.

Additional Sources of Information: Recovery Strategy for the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) – Carolinian population in Canada [Proposed] (Environment and Climate Change Canada 2016).

Status and reasons for designation:

Status: Endangered

Alpha-numeric codes: B1ab(iii, v)+2ab(iii, v); C2a(i); D1

Reasons for designation: This salamander with aquatic larvae inhabits forested brooks, cascades, springs, and seeps, where there is abundant cover in the form of crevices between stones, logs, or leaf litter. Its entire Canadian distribution is confined to two streams within a small area of Niagara Gorge, Ontario, and is isolated from other populations in Canada and in the United States. Increased survey effort within the past decade has expanded the known area of occupancy from one to two streams. However, the small range and population size, probably fewer than 100 adults, makes this salamander highly susceptible to environmental fluctuations and chance events, and effects of human activities. The population would be lost if the groundwater flow or water quality in the two streams would become compromised by human activities or effects of climate change.

Applicability of criteria

Criterion A Decline in Total Number of Mature Individuals): Not applicable. Although there is a projected decline in the number of adults based on threats, its magnitude is unknown.

Criterion B (Small Distribution Range and Decline or Fluctuation): Meets Endangered, B1ab(iii,v)+2ab(iii,v), because both EOO and IAO are below threshold values, there are fewer than 5 locations, there is an observed and projected decline in habitat quality, and a projected and inferred decline in number of mature individuals.

Criterion C (Small and Declining Number of Mature Individuals): Meets Endangered, C2a(i), because the population size is below threshold and there is a continuous observed and projected decline based on threats; neither of the two subpopulations is greater than 250 mature individuals.

Criterion D (Very Small or Restricted Total Population): Meets Endangered, D1, because the population size is most likely less than 250 adults. Meets Threatened, D2, because the small population is prone to human activities and stochastic events, which over a short period could lead the population to become critically endangered should these activities/events affect the ground water that feeds all occupied streams.

Criterion E (Quantitative Analysis): Not done due to insufficient data.

Preface

Since the previous assessment of Allegheny Mountain Dusky Salamander in 2007, surveys have made it possible to more precisely identify the area of occupancy in Québec and have led to the discovery of a new site in Ontario. Despite search efforts, there are only two small populations in Canada. Both have a limited distribution and are isolated from each other with no possibility of gene flow between them or with U.S. populations. Population trends remain unknown. In 2016, one of the Ontario sites was accidentally contaminated by a grout spill, which could have negative effects on the species in the future. Recent studies have provided a better understanding of threats and limiting factors. New potential threats have been identified, including atmospheric deposition of pollutants, watershed urbanization, nitrate contamination, and disease, and the effect of climate change on the Covey Hill aquifer has been examined. Genetic analyses of the congeneric D. fuscus suggest that fragmentation and urbanization can lead to population differentiation, genetic variation, and bottlenecks even at small spatial scales.

COSEWIC history

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2018)

Wildlife species

A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.

Extinct (X)

A wildlife species that no longer exists.

Extirpated (XT)

A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.

Endangered (E)

A wildlife species facing imminent extirpation or extinction.

Threatened (T)

A wildlife species likely to become endangered if limiting factors are not reversed.

Special concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)

A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.

Not at risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)

A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)

A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment and Climate Change Canada, provides full administrative and financial support to the COSEWIC Secretariat.

Wildlife species description and significance

Name and classification

Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus; Cope 1859) is a member of the family Plethodontidae (lungless salamanders) (Gray 1850). This diverse family of salamanders includes 453 currently recognized species (Frost 2015). The genus Desmognathus, which currently includes 23 species of “dusky salamanders,” is part of the subfamily Plethodontinae, which comprises 100 species (Frost 2015). Only two representatives of the genus are found in Canada: Northern Dusky Salamander (Desmognathus fuscus) and Allegheny Mountain Dusky Salamander (D. ochrophaeus).

Allegheny Mountain Dusky Salamander is the only Canadian member of the D. ochrophaeus complex, which includes seven ecologically and morphologically similar species: D. abditus, D. appalachicolae, D. carolinensis, D. imitator, D. ochrophaeus, D. ocoee, and D. orestes (Tilley and Mahoney 1996; Anderson and Tilley 2003; Frost 2015). Despite their distinct geographic ranges, these species are closely related and can hybridize in areas where they come in contact; genetic analyses can be used to distinguish them (Tilley and Mahoney 1996; Petranka 1998; Mead and Tilley 2000; Anderson and Tilley 2003). For many years, interpretations of geographic variation in morphology within the group caused unstable nomenclature and debate about the taxonomic status (Petranka 1998). Genetic analyses of allozyme variation made it possible to subdivide D. ochrophaeus into several genetically differentiated allopatric forms (Tilley and Mahoney 1996; Mead and Tilley 2000; Tilley 2000; Anderson and Tilley 2003; Beamer and Lamb 2008). The name D. ochrophaeus is now restricted to northern populations that extend from Tennessee northward (Petranka 1998).

Hybridization between Allegheny Mountain Dusky Salamander and Northern Dusky Salamander has been documented in some sympatric populations in Pennsylvania and Ohio and been infrequently noted in the Covey Hill population in Canada (Karlin and Guttman 1981; Sharbel and Bonin 1992; Sharbel et al. 1995; Boutin 2006).

Frost (2015) reviewed the various scientific and English common names previously proposed for the Allegheny Mountain Dusky Salamander, including Desmognathus ochrophea (Cope 1859; Dunn 1917), Plethodon ochrophaeus (Smith 1877), Yellow Desmognath (Jordan 1878), Gray Salamander (Rhoads 1895), Yellow Salamander (Brimley 1907), Allegheny Mountain Salamander (Schmidt 1953; Conant et al. 1956), and Mountain Dusky Salamander (Conant 1975). The currently accepted standard names are Allegheny Mountain Dusky Salamander in English and salamandre sombre des montagnes in French (Green 2012; Moriarty 2012).

Morphological description

Dusky salamanders (i.e., members of the genus Desmognathus) have a stout body and hind limbs that are conspicuously larger than their front limbs. A pale line that extends from the eye to the angle of the jaw is diagnostic and can be used to distinguish these salamanders from other plethodontids (Conant and Collins 1998; Desroches and Rodrigue 2004).

Allegheny Mountain Dusky Salamander is a small, slender salamander with 14 costal grooves (Petranka 1998). Its tail, which is rounded and lacks a keel, is slightly longer than its body (Conant and Collins 1998; Petranka 1998). Adults reach a total length (TL) of 70 to 100 mm; males are generally longer than females (Orr 1989; Bruce 1993). A male with 107 mm TL (58 mm SVL) is among the largest specimens caught in Niagara (A. Boutin, per. obs.).

Allegheny Mountain Dusky Salamander exhibits considerable variation in colouration, which changes with age (Martof and Rose 1963; Tilley 1969;Petranka 1998). The species has a light mid-dorsal stripe that extends from the head to the tail. It may be yellow, orange, olive, grey, brown, or reddish and sometimes becomes less visible with age (Conant and Collins 1998; Petranka 1998; Desroches and Rodrigue 2004). The mid-dorsal stripe is bordered by very dark, sometimes black, pigment that fades into the lower sides (Conant and Collins 1998; Figure 1). Adults and juveniles have a straight-edged dorsal stripe, but in southern populations the stripe tends to be wavy (Tilley 1969; Conant and Collins 1998). The species has grey sides with small white spots that become more concentrated near the ventral surface (Conant and Collins 1998; Petranka 1998). The ventral surface is usually light grey and darkens with age (Petranka 1998). The dorsal patterns of the Allegheny Mountain Dusky Salamander are also variable and can become less apparent with age (Tilley 1969; Conant and Collins 1998; Petranka 1998). The mid-dorsal stripe commonly has a central row of chevron-shaped dark spots (Conant and Collins 1998; Petranka 1998; Figure 1). Older individuals, especially males, tend to become melanistic or uniformly dark with age (Dunn 1926; Martof and Rose 1963; Tilley 1969; Petranka 1998).

Allegheny Mountain Dusky Salamander larvae measure 13 to 18 mm TL and have gills, prominent yolk reserves, and a tail that is laterally compressed on the dorsal and ventral surfaces, forming a fin (Bishop and Chrisp 1933; Bishop 1941; Huheey and Brandon 1973; Orr 1989). They have a uniformly light yellowish or reddish mid-dorsal stripe and either lack spots along the dorsum or have them restricted to the posterior portion of the trunk (Bishop and Chrisp 1933; Orr 1989; Petranka 1998). This stripe is flanked by dark pigments that extend from the sides forming straight dorsolateral lines (Bishop and Chrisp 1933). The larvae of Allegheny Mountain Dusky Salamander can be distinguished from those of D. fuscus by the absence of pairs of large light spots bordered by dark pigments on the dorsal stripe (Bishop and Chrisp 1933).

Allegheny Mountain Dusky Salamander may be confused with Northern Two-lined Salamander (Eurycea bislineata) or Eastern Red-backed Salamander (Plethodon cinereus). However, it can be distinguished from these two species by the presence of a pale line that extends from the eye to the angle of the jaw and by its rear limbs, which tend to be conspicuously larger than its front limbs. In addition, the underside of Northern Two-lined Salamander is a characteristic yellow colour.

Northern Dusky Salamander (D. fuscus) is similar in appearance and occupies similar habitats. That species can be recognized by its mid-dorsal stripe, which has irregular or wavy edges and lacks chevron-shaped marks (Conant and Collins 1998; Petranka 1998; Desroches and Rodrigue 2004). Unlike in Allegheny Mountain Dusky Salamander, the dark spots on the dorsum of D. fuscus do not form a central line(Conant and Collins 1998; Petranka 1998; Desroches and Rodrigue 2004). The shape of the tail may aid in differentiating the species: Allegheny Mountain Dusky Salamander has a round, slender tail, whereas that of D. fuscus is slightly compressed laterally and has a keel, making it appear triangular in cross-section (Bider and Matte 1996; Conant and Collins 1998; Petranka 1998). However, researchers were unable to use this trait successfully to differentiate Allegheny Mountain Dusky Salamander and Northern Dusky Salamander at sites where the two species were sympatric in Québec (A. Boutin, unpubl. data).

The overlapping ranges of Allegheny Mountain Dusky Salamander and Northern Dusky Salamander, their high level of intraspecific variation, and their propensity for hybridization have presented challenges for field identification in areas of sympatry (Tilley 1973; Karlin and Guttman 1981; Bonin 1993; Sharbel et al. 1995). Morphological characters can generally be used to identify them successfully; however, within zones of hybridization, molecular analysis may be necessary (Sharbel and Bonin 1992; Tilley and Mahoney 1996; Tilley 1997; Boutin 2006).

Population spatial structure and variability

The two Canadian populations of Allegheny Mountain Dusky Salamander are located near the Canada-United States border, but they are separated from U.S. populations by geographic distance or by physical barriers. The Covey Hill, Québec, population is located about 12 km east of the closest population in New York State. The Niagara, Ontario, population is close to the neighbouring U.S. populations but is separated by the Niagara River at the bottom of the Niagara Gorge. Rivers and large streams can act as barriers to salamander dispersal (Howard et al. 1983; Bonett and Chippindale 2004; Markle 2006), and hence the fast-flowing Niagara River is likely a significant barrier to gene flow. No Allegheny Mountain Dusky Salamanders are known from within the Niagara Gorge on the New York side; the closest population is located 22 km farther east along the Niagara Escarpment in New York State. It is not known how long populations on either side of the border have been separated, or whether geographic isolation may have generated genetic differences between the U.S. and Canadian populations or between the Canadian populations.

As part of a molecular study undertaken to determine if the Niagara population of Allegheny Mountain Dusky Salamander was genetically distinct from neighbouring U.S. populations, mitochondrial DNA sequences (22 loci) from 19 Niagara Gorge specimens, and 30 specimens from six localities in western New York State were compared (Markle and Green 2006). The comparison of gene sequences, Cyt b (378 bp) and 12S rRNA (576 bp), did not reveal any significant genetic variation between the populations or localities (Markle and Green 2006). Based on allozymes, Tilley (1997) found little genetic variation between nine northern subpopulations of Northern Dusky Salamanders over distances up to 1,000 km. These results should be taken cautiously, however, because they rely on methods that may not effectively detect genetic variability and population differentiation; microsatellites are more suitable (N. Tessier pers. comm. 2015).

The Covey Hill population is believed to be a relatively small, genetically isolated, inbred unit with a small percentage of individuals occasionally interbreeding with Northern Dusky Salamander (Sharbel et al. 1995). Inbreeding might be even more pronounced in the Niagara population, given its small size. Because Canadian populations are small and isolated and do not receive immigrants from populations outside of Canada, they are expected to diverge over time; they are also at risk of genetic impoverishment (N. Tessier pers. comm. 2015). A study conducted in New York City using five microsatellite markers showed that isolated populations ofthe congeneric Northern Dusky Salamander, a species that was once widely distributed there, had a very low level of genetic diversity (< 20% heterozygosity). The results also showed that the majority of subpopulations exhibited evidence of genetic bottlenecks (Munshi-South et al. 2013). The lowest levels of heterozygosity (H0=0.14 and H0=0.29) were found in specimens from two nearby seep areas, which are separated by two bridges that together have 14 traffic lanes (Munshi-South et al. 2013). These two subpopulations presented different genetic structures (N= 67, Fst=0.08, p=0.001) and one of them had 11 unique alleles, indicating that they are completely isolated and have evolved independently (Munshi-South et al. 2013). These two populations were also differentiated from those located on the other side of the Hudson River (Munshi-South et al. 2013). This study also found greater allelic richness in populations located in larger, protected habitats compared with those in fragmented habitats (Munshi-South et al. 2013). Similar results could be expected in Niagara, as the two localities are separated by distance and a bridge as well. The Niagara River could also promote genetic divergence between Niagara and US populations. The Covey Hill population, comprising multiple streams within a larger patch of suitable habitat, could presumably display greater allelic richness compared to the Niagara population. To date, no genetic comparisons have been made between the two Canadian populations of Allegheny Mountain Dusky Salamander, or between the Covey Hill population and populations south of the border. A project is currently underway to compare the Niagara and Québec populations based on microsatellites (N. Tessier and A. Boutin, unpubl. data). It is hoped this study will provide information on isolation, prevalence of inbreeding, long-term prospects for population persistence, and potential for evolutionary responses to future environmental change (Munshi-South et al. 2013).

In the southern part of the range of Allegheny Mountain Dusky Salamander, local and regional differentiations have often been suspected, based on marked differences in phenotype, morphology, demography, and population structure and dynamics, or based on the sexual incompatibility of certain parapatric forms (Martof and Rose 1963; Tilley 1969, 1974, 1980; Tilley et al. 1990; Herring and Verrell 1996).

Hybridization between Allegheny Mountain Dusky Salamander and Northern Dusky Salamander was first suspected from the observation of specimens that were morphologically intermediate between the two species (Dunn 1926; King 1939; Hairston 1949; Martof and Rose 1963). Protein (allozyme) electrophoresis carried out on 26 genes (of which 14 were invariant, 8 permitted differentiation of the two species, and 4 were almost discriminant) subsequently confirmed the presence of hybrids in sympatric populations in Ohio and Pennsylvania (Karlin and Guttman 1981). Natural hybrids were also detected in Covey Hill, Québec, where the two species are in contact (Sharbel and Bonin 1992; Sharbel et al. 1995; Boutin 2006). The absence of first-generation (F1) hybrids resulting from crossing between the two pure parental species (i.e., heterozygous at all loci studied) indicates that hybridization is infrequent (Karlin and Guttman 1981; Sharbel et al. 1995). Based on allozyme variation, Sharbel et al. (1995) detected 11 hybrids of 201 specimens. Among 49 suspected hybrids, based on morphological characters, Boutin (2006) confirmed 12 to be hybrids based on mitochondrial and nuclear DNA markers. The great majority of hybrids appear to be backcrosses with Allegheny Mountain Dusky Salamander (Karlin and Guttman 1981; Sharbel et al. 1995; Boutin 2006).

Given the presence of distinct lineages of Desmognathus across small and sometimes overlapping ranges, it appears that other factors besides geographic distance also promote local genetic differentiation in this group (Beamer and Lamb 2008). Biotic interactions (Tilley 1997), historical events (Rissler and Taylor 2003), climatic gradients (Kozak and Wiens 2006), barriers to dispersal, and urban fragmentation (Munshi-South et al. 2013) are all factors that appear to promote genetic differentiation of Desmognathus on a landscape scale.

Designatable units

Genetic differences between the Covey Hill, Québec, and the Niagara, Ontario populations of Allegheny Mountain Dusky Salamander have not been examined but given their isolation and small population sizes such differences and local adaptations are expected. These two populations qualify as separate COSEWIC designatable units (DUs; (COSEWIC 2015a) because of the following:

• They are geographically isolated from each other and are separated from the rest of the species’ distribution by geographic distance and by natural physical barriers, such as the Niagara River (see Population Spatial Structure and Variability). The species’ limited dispersal ability prevents the possibility of exchange of individuals between the two units and satisfies the criteria for discreteness. While a connection in the overall range exists through the United States, the salamanders are patchily distributed across this range, and their dispersal capabilities are limited by physiological constraints and habitat discontinuities
• They also satisfy the criteria for significance because their isolation and environmental conditions within the two areas may have given rise to local adaptations, such as documented for related species of salamanders. The two populations occur in different COSEWIC Terrestrial Amphibian and Reptile Faunal Provinces (Carolinian and Great Lakes/ St. Lawrence, 2007 map; Appalachian for the latter in the 2016 map), further supporting this DU structure, but supporting genetic information is lacking

Special significance

Dusky salamanders have been a popular research subject in the areas of systematics, evolution and biogeography because of their remarkable diversity (Danstedt 1975; Rissler and Taylor 2003; Kozak et al. 2005). Dusky salamanders provide an opportunity to gain insights into speciation and reproductive isolation (Arnold et al. 1993). In Canada, Allegheny Mountain Dusky Salamander is of special interest because it is the only Canadian member of the D. ochrophaeus complex and is at the northern limit of its global distribution in North America. The small size of the two Canadian populations makes them interesting research units, and their isolation may give them unique traits that are absent from U.S. populations.

Stream salamanders are significant predators in headwater streams lacking predatory fish (Hairston 1949; Petranka and Murray 2001; Southerland et al. 2004), and they play a role in trophic transfer, energy flow, and nutrient cycling (Burton and Likens 1975a; Wyman 1988; Davic and Welsh 2004; Keitzer and Goforth 2013). Salamanders can be the dominant vertebrates within headwater/riparian forest ecosystems (Burton and Likens 1975a,b; Hairston 1987; Petranka and Murray 2001). Stream salamanders are excellent indicators of ecosystem health (Welsh and Ollivier 1998; Southerland et al. 2004). Dusky salamanders are highly sensitive to forest disturbances (Moseley et al. 2008; Ward et al. 2008), pollution, sedimentation (Orser and Shure 1972; Brannon and Purvis 2008; Moseley et al. 2008), and mining activities (Wood and Williams 2013; Muncy et al. 2014).

Distribution

Global range

Allegheny Mountain Dusky Salamander ranges throughout the Appalachian Mountain System of eastern North America (Figure 2). The species’ distribution extends from the Adirondack Mountains of northern New York State, west to northeastern Ohio, east to northern New Jersey, and south through all of Pennsylvania, except the southeastern quarter, northeastern Maryland, eastern West Virginia, extreme western Virginia, the eastern and central area of Kentucky, to northern Tennessee. The area of Covey Hill, Québec, in Canada is at the extreme northern limit of the species’ range. The species is absent from Vermont and US states farther east, suggesting that Lake Champlain acts as a geographic barrier to the species’ eastward dispersal (NatureServe 2015; IUCN 2016). Allegheny Mountain Dusky Salamander is also absent from Delaware and the District of Columbia (NatureServe 2015; IUCN 2016). The global range of Allegheny Mountain Dusky Salamander, as formerly known, has decreased slightly because of the recognition of two distinct species in the southern portion of its U.S. range (Tilley and Mahoney 1996; NatureServe 2015; IUCN 2016). North Carolina, South Carolina, Georgia, and Alabama are no longer included in the range of Allegheny Mountain Dusky Salamander, as described in the previous status report for this species (COSEWIC 2007).

Canadian range

In Canada, Allegheny Mountain Dusky Salamander occurs in a few streams and seeps on the northern side of a hill known as Covey Hill in Québec and in two streams in the Niagara Gorge in Ontario (Figure 3). A historical record from the Saint John River, New Brunswick (Logier 1952), appears to be attributable to a misidentification (COSEWIC 2007).

The species was first discovered in Québec in 1988, but its identification (through protein electrophoresis) was not validated until 1990 (Sharbel and Bonin 1992). Despite searches undertaken in other mountainous areas of Québec, the species has only been found in this small locality in the Adirondack Foothills, which is surrounded by unsuitable habitat (i.e., agricultural or urbanized lowlands). It is separated from the nearest populations in New York State by about 12 km, and from the other Canadian population by 100s of kilometres.

Dusky salamanders were first reported from Ontario in 1908 (Nash 1908), although a general area was not mentioned until Bishop (1943) reported the presence of dusky salamanders in “Ontario opposite Buffalo, New York” (Markle et al. 2013). The first specific locality of these salamanders was documented in 1989, when Northern Dusky Salamander was discovered at two sites in the Niagara Gorge (Kamstra 1991). Genetic analyses subsequently revealed that the specimens from one of these sites were actually Allegheny Mountain Dusky Salamander (Markle and Green 2005, 2006; Markle et al. 2006, 2013).

Until 2010, the species was known from only a single stream near the Niagara River, referred here as Stream 1. Surveys carried out in 2010 led to the discovery of the species at a second locality, referred here as Stream 2, over 350 m from Stream 1 (Weller 2010, 2011, 2012, 2013; Markle et al. 2013).

The Niagara Gorge population in Ontario now comprises salamanders in two streams that flow over a rocky escarpment with a very steep gradient and drain into the Niagara River, bordered at the top by a heavily urbanized tableland (Yagi and Tervo 2008; Weller 2010, 2011). The neighbouring populations in New York State are located on the other side of the gorge, about 22 km away from Stream 1 (COSEWIC 2007). The Canadian and US populations are separated by the Niagara River and the heavily urbanized city of Niagara Falls, New York, and the town of Lewiston, New York, all of which represent major barriers to dispersal by the salamanders (Markle et al. 2013).

The species’ range in Canada remains very restricted and represents less than 1% of its global range (Figure 1; IUCN 2016). A few unexplored areas of the Niagara Gorge, Niagara Escarpment, and Fonthill Kame Moraine are among the only sites that may have suitable habitat for the species in Ontario (Markle et al. 2013). Although numerous stream salamander surveys have been undertaken in Québec and Ontario (see Search Effort), the Covey Hill and Niagara populations remain the only known Allegheny Mountain Dusky Salamander populations in the Canada.

Extent of occurrence and area of occupancy

Based on the information available in 2015, the extent of occurrence of the species is 60 km², of which 56 km² is occupied by the Appalachian (Covey Hill) population and less than 4 km² by the Carolinian population (Niagara Gorge). The extent of occurrence was determined on the basis of the smallest convex polygon encompassing all recent (1999 to 2015) observations of the species (COSEWIC 2015b).

The surveys carried out in Québec and Niagara, Ontario, have helped to refine the distribution of Allegheny Mountain Dusky Salamander and produced new observations within the area of occupancy (Figure 4; A. Filion pers. comm. 2015). The index of area of occupancy (IAO) of the species is 60 km², in total, of which 56 km² is at Covey Hill and 4 km² at Niagara Gorge (Appendices 1 and 2). This index is obtained by superimposing a grid with a cell size of 2 km x 2 km on the species’ area of occupancy and counting the number of cells occupied by the species (COSEWIC 2015b). The actual area of occupancy is much smaller and covers only approximately 0.4 km² for the Niagara Gorge population.

Search effort

Since the discovery of the Northern Dusky Salamander in Québec in 1928, considerable efforts have been devoted to searching for dusky salamanders in the province (BORAQ 2015). As of the late 1950s, a number of surveys targeting Northern Dusky Salamander were undertaken in the Appalachians in Québec and in the Maritimes (Bleakney 1958; Cook and Bleakney 1960; Denman 1963; Pendlebury 1973; Weller 1977; Weller and Cebek 1991a). Because Allegheny Mountain Dusky Salamander occupies habitats similar to those of Northern Dusky Salamander, searches for the latter species should also result in the detection of Allegheny Mountain Dusky Salamander. In Québec, the Centre de données sur le patrimoine naturel du Québec (CDPNQ) compiles negative data (i.e., sites where the species was sought unsuccessfully) associated with the stream salamander survey (Appendix 3).

Surveys for dusky salamanders have been carried out in various regions of Québec, but no observations of Allegheny Mountain Dusky Salamander have been made. Considerable search efforts were deployed in the Québec City area after Northern Dusky Salamander was discovered there in 1987 (Supplementary information available from COSEWIC on request). The search effort included several sites near Québec City and on Ile d’Orléans (Bider and Matte 1994; Bonin 1999; Desroches and Pouliot 2005; Pouliot and Vallières 2007; Pouliot et al. 2007). All the islands in the St. Lawrence estuary were surveyed in 1992 –2003 (Fortin et al. 2004), as was Ile aux Coudres (Pouliot et al. 2007), albeit without success. In 2010, habitats potentially suitable for Northern Dusky Salamander were visited on the north shore of the St. Lawrence River, along the eastern edge of this species’ range, as well as in the Portneuf area (C. Laurendeau, in prep.). More than 90 new occurrences of Northern Dusky Salamander were identified without a single observation of Allegheny Mountain Dusky Salamander (C. Laurendeau, in prep.). A specimen morphologically assigned to Allegheny Mountain Dusky Salamander was found on Mount Mégantic in 2010, but genetic analyses confirmed that it was Northern Dusky Salamander (A. Boutin and N. Tessier, unpubl. data). Markle (2006) conducted surveys for Northern Dusky Salamander at 58 sites in Québec and Labrador involving a search effort of 100 to 150 hours (Markle 2006; Supplementary information available from COSEWIC on request). The Appalachian Corridor Appalachien (ACA) organization and Envirotel have been conducting stream salamander surveys along the Sutton Mountain Range in the Appalachians since 2001 (Table 1). Surveys have also been conducted along streams on Mont Sutton, near Lake Massawippi, and in the Rivière aux Saumons watershed, without success (Table 1, Desroches and Picard 2001; Frenette 2007). Amphibian surveys involving the combined use of various techniques (active diurnal searches, nocturnal observations, pitfall traps, nets, and drift fences) were conducted on seven Monteregian Hills between 1997 and 2004 and in the Mont St. Hilaire Biosphere Reserve from 1997 – 2002 (Ouellet et al. 2004, 2005; Noël et al. 2007; (Supplementary information available from COSEWIC on request). A total of 70 wetlands in the Eastern Townships were surveyed for Northern Dusky Salamander (Frizzle 2001); this survey and a herpetofauna survey conducted in a 467 ha of forest on the Monteregian Plain from 2002 – 2004 failed to locate any dusky salamanders (Galois and Ouellet 2005). Active searches for salamanders carried out in forested habitats in the Montréal area and on islands in the Greater Montréal Area (Noël-Boissonneault 2009; N. Tessier and Éco-Nature, unpubl. data) suggest that dusky salamanders are absent from the Greater Montréal Area (Table 1).

^a Effort in person-days
^b Area searched using an active search method (i.e., turning over all potential cover items)
^c Stream sections 25 m long with search extending up to 2 m from water’s edge

Numerous other field surveys for stream salamanders have been conducted in Québec (Gordon 1979; Bonin 1989; Shaffer and Bachand 1989; Denman et al. 1990; Weller and Cebek 1991a,b,c; Bider and Matte 1991, 1996; Boutin 2004, 2006; Bouthillier 2011; MRNF and CNC 2012; CNC 2013; Laurendeau, in prep.). No other occurrences of Allegheny Mountain Dusky Salamander have been found, and Covey Hill is believed to be the only locality where the species occurs in the province. Individual salamanders were observed on a number of occasions at Covey Hill in the 1990s (Bonin 1999; Bider and Matte 1994) and again in 2002 – 2004 during systematic surveys for Allegheny Mountain Dusky Salamander in stream sections in three areas at Covey Hill, for a total search effort of 210 person-days (Table 2, Jutras 2003; Boutin 2006; Frenette 2007). Since 2002, the Nature Conservancy of Canada (NCC/CNC) has completed many stream salamander surveys at Covey Hill, which has increased the number of records of Allegheny Mountain Dusky Salamander and helped to better delineate its distribution there (CNC 2015). From 2002 – 2014, nearly 42% of the natural area of Covey Hill was surveyed (CNC 2015; (Supplementary information available from COSEWIC on request). The Covey Hill salamander population has a small area of occupancy in a sector where the potentially suitable habitat for the species covers a maximum area of 70 km² (C. Deland pers. comm. 2015). It is unlikely that suitable habitat for Allegheny Mountain Dusky Salamander will be identified elsewhere. The species normally occupies headwater streams at higher elevations, which are in limited supply.

^d Area searched using an active search method (i.e., turning over all potential cover items)
^e Stream sections 25 m long or seepage area with search extending up to 2 m from water’s edge

At the Niagara Gorge site, surveys for Allegheny Mountain Dusky Salamander were conducted using cover boards and active searching from 2004 – 2008 to monitor the population (Table 2). These efforts led to a considerable increase in observations of the salamanders at known sites (A. Yagi, unpubl. data; NHIC 2015). The rugged terrain and steep slopes that characterize the Gorge make it difficult to access habitats and impose major safety constraints (W. Weller pers. comm. 2015); these constraints limit the possibility of conducting searches along the Niagara River (Markle et al. 2013). Efforts were made to identify suitable habitat at Niagara-on-the-Lake, St. Catharines, and Grimsby, as well as north of the Sir Adam Beck I generating station (6 person-hours) (Table 2; Appendix 4 [sensitive information removed]). A potential site was identified south of Queenston, but limited searches there failed to turn up any specimens of dusky salamanders (W. Weller pers. comm. 2015); this site is completely isolated from the two known localities. In 2016, searches for Allegheny Mountain Dusky Salamander were carried out at Stream 1 for a total search effort of 10.9 person-hours (A. Boutin, unpubl. data; Table 2). For the first time, the survey covered the entire stream, from its source to areas downstream from sites where the species is known to have been present (A. Boutin, unpubl. data). In September 2016, a search effort of 2.7 person-hours was devoted to finding the species at the Stream 2 locality by visiting known habitats and areas farther upstream (Table 2; A. Boutin, unpubl. data).

The presence of Allegheny Mountain Dusky Salamander in New Brunswick has not been confirmed. The only record of Allegheny Mountain Dusky Salamander in New Brunswick (Logier 1952) was based on a misidentification (COSEWIC 2007). In 2010 – 2011, searches for dusky salamanders led to an expansion of the known range of Northern Dusky Salamanderto the north and east of the province, but no observations of Allegheny Mountain Dusky Salamander were made (COSEWIC 2012).

Habitat

Habitat requirements

Allegheny Mountain Dusky Salamander lives near small, slow-flowing streams, springs, seeps, wet rocky outcrops and seepage areas with cold, well-oxygenated water in forested habitats (Green and Pauley 1987; Conant and Collins 1998; Petranka 1998). It is usually absent from large, fast-flowing streams where predatory fish occur (Conant 1975; Rutherford et al. 2004; Boutin 2006). In the United States, the species is found at a wide range of elevations from 168 m – 1280 m (Tilley and Mahoney 1996; NatureServe 2015). At Covey Hill, the species is found at elevations from 87 – 328 m (Sharbel et al. 1995; BORAQ 2015); most observations (69%; n = 212) are from elevations above 162 m (C. Laurendeau pers. comm. 2015). On the Niagara Escarpment, the species has been observed at elevations from 80 m – 180 m (NHIC 2015).

At Covey Hill, Allegheny Mountain Dusky Salamander is found in seepage areas and narrow, small, cool, and shallow intermittent streams that are fed by groundwater (Sharbel et al. 1995; Boutin 2006). The majority (80%) of the 98 specimens found at this locality in 2004 were in intermittent streams (Rutherford et al. 2004; Boutin 2006). Others were found along the margins of slow-flowing permanent streams with discharge not exceeding 0.009 m3/s (Rutherford et al. 2004; Boutin 2006). At Niagara Gorge, the species occupies groundwater seeps in very steep rock outcrops (Yagi and Tervo 2008; Markle et al. 2013). At Stream 1, the species is distributed along a 2 m – 5 m wide seepage and in small pools away from the main section of the stream (Yagi and Tervo 2008). At Stream 2, it is found within an area of under 1 km² (Weller pers. comm. 2015).

Microhabitat

Allegheny Mountain Dusky Salamander usually selects habitats with fine substrates (humus, silt, gravel-silt mix) containing large amounts of organic matter in which it can burrow (Krzysik 1979; Boutin 2006; Environment Canada 2014). The abundance of Desmognathus salamanders is positively correlated with the presence of leaf litter and is influenced by various factors such as elevation, stream size, availability of cover objects, and the presence of other salamander species (Southerland 1986a; Orser and Shure 1972). To minimize water loss, Allegheny Mountain Dusky Salamander remains in cool, moist retreats during the day (Petranka 1998). The salamanders hide under cover objects (stones, woody debris, moss, leaf litter) or in underground burrows near a water source (Green and Pauley 1987; Petranka 1998). These retreats are essential: they provide protection from dehydration and predation, in addition to providing habitat for foraging, egg-laying, and egg development (Petranka 1998). The species is positively associated with the presence of large rocks on the stream bed and along the edges of streams (Krzysik 1979; Boutin 2006). These cover objects help retain soil moisture and harbour abundant prey items, which can be captured without leaving the retreat (Jaeger et al. 1995; Grover 2000). Rocks and woody debris provide better protection from predation than leaf litter, in which salamanders are more accessible to birds and to mammalian predators (Moore et al. 2001). In dense populations, streambank burrows are monopolized by large salamanders, while juveniles and smaller individuals use stream bed retreats (Southerland 1986a). Streambank burrows offer the advantage of being more permanent than stream bed retreats, as they are not affected by water level fluctuations or the flow trajectory (Southerland 1986a). The addition of cover objects to streams can result in a local increase in densities of Desmognathus salamanders despite the presence of predators. In control plots with cover objects occupying 25% of the total area, the average number of salamanders under each object was 1.5; the number increased to 2.8 when cover objects were added to encompass 75% of plot area (Southerland 1986a).

The availability of suitable refuges regulates the distribution, abundance, and composition of stream salamander communities (Southerland 1986a; Grover 1998). In the evening and during periods of high humidity, Allegheny Mountain Dusky Salamanders leave their retreats to forage across the forest floor adjacent to the stream (Weber 1928; Green and Pauley 1987; Pauley 1995a in Pauley and Watson 2005). Desmognathine salamanders sometimes remain under the same cover object for several days, but they are more likely to shift refuges after a night of surface activity (Southerland 1986b). When moisture conditions change significantly over short periods, they shift refuges frequently (Southerland 1986b). Allegheny Mountain Dusky Salamanders may sometimes venture far from a water source, usually in an upstream direction (Weber 1928; Green and Pauley 1987; Pauley 1995a in Pauley and Watson 2005); however, like Northern Dusky Salamanders, they require moist habitats nearby for rehydration (Pasachnik and Ruthig 2004).

Egg-laying habitat

Females lay their eggs in shallow depressions in moist, unconsolidated, fine substrates beneath moss, rocks, logs, stumps, or woody debris that is partly embedded in mud (Bishop 1941; Keen and Orr 1980; Hom 1987). They move upslope along the stream corridor to seek cryptic microhabitats at the terminus of headwater streams, in dried-up stream beds or in riparian habitats adjacent to springs, seeps or shallow first-order streams (Bishop and Chrisp 1933; Bishop 1941; Orr 1989). Compared with other members of the species complex, Allegheny Mountain Dusky Salamander has a strong tendency to nest underground (Keen and Orr 1980). Nests are generally found 0.5 m from a water source (Pauley 1993b in Pauley and Watson 2005) but may be at a considerable distance from surface water (Wood and Wood 1955). The soil must be constantly saturated to permit development of the eggs (Bishop 1941).

Habitats of larvae and juveniles

The larvae are able to survive in intermittent sources of water (Environment Canada 2014). They can be found in seepage areas, springs, seeps, or sluggish portions of streams, where they occupy muddy habitats with plenty of moss or organic matter (Petranka 1998). These habitats may have little surface water but must be moist at all times. Larval development requires a constant supply of cool, well-oxygenated water and may be compromised by drought conditions or stream acidification (Green and Peloquin 2008). The ability of Allegheny Mountain Dusky Salamander larvae to survive in intermittent streams, in which other stream-dwelling salamander (D. fuscus, E. bislineata and G. porphyriticus) larvae cannot survive, is undoubtedly a means of reducing competition and interspecific predation (COSEWIC 2007).

Metamorphosed juveniles use habitats similar to those of adults (Pauley and Watson 2005). Although they use the same types of cover objects, they are observed more frequently under and between damp leaves on the forest floor and at the edges of first-order streams (Pauley and Watson 2005). The smallest individuals may use smaller cover

objects and move farther away from water to avoid competition with larger individuals of their species (Pauley and Watson 2005). Small individuals are able to use small cover objects and hide in small interstitial spaces in the substrate, which are less accessible to predators and larger salamanders (Krzysik 1979).

Habitat use in relation to other salamanders

Allegheny Mountain Dusky Salamander is among the most terrestrial species in the genus Desmognathus (Conant and Collins 1998). In southern Pennsylvania, seepage areas isolated from permanent streams and intermittent streams without open water are the only habitats where Allegheny Mountain Dusky Salamander has been found alone without the presence of other salamanders (Krzysik 1979). This is also the case in Ontario and in certain seeps in Québec (Markle et al. 2013; CNC 2015). In other habitats, the species sometimes coexists with other terrestrial and semi-aquatic salamanders. In Québec, Allegheny Mountain Dusky Salamander sometimes occurs alongside Northern Dusky Salamander, Northern Two-lined Salamander, Spring Salamander (Gyrinophilus porphyriticus), and Eastern Red-backed Salamander (Boutin 2006). Allegheny Mountain Dusky Salamander uses finer, drier substrates farther from open water when in the presence of Northern Dusky Salamander(Hall 1977; Krzysik 1979). In comparison withEastern Red-backed Salamander, Allegheny Mountain Dusky Salamander nonetheless requires cooler, moister habitats for foraging and egg-laying (Pauley 1980b in Pauley and Watson 2005).

At Covey Hill, Allegheny Mountain Dusky Salamander moves away from streams presumably to avoid competition and predation by other salamanders, but they may recolonize these sites during dry periods (Boutin 2006). In view of this situation, the species’ habitat needs to include a variety of suitable microhabitats into which the salamanders can disperse in response to changes in hydrologic conditions and competition and predation (Bonin 1993).

Over-wintering habitat

During winter, Allegheny Mountain Dusky Salamanders remain near springs, seeps, and peat bogs (Green and Pauley 1987). In New York State, they may congregate in moist habitats adjacent to springs, streams, and seeps in headwater areas of watersheds (Bishop 1941). Surface activity is greatly reduced when the air temperature drops to 0 – 5°C (Keen 1979), when the salamanders move into retreats under rocks, woody debris, moss and leaf litter, where they can avoid sub-zero temperatures and where the substrate is saturated (Organ 1961; Ashton 1975; Ashton and Ashton 1978). During cold periods, the salamanders migrate vertically to subterranean refugia (Keen 1979), where they remain just above groundwater levels (Hairston 1949); depths of up to 90 cm below the ground surface have been reported for Carolina Mountain Dusky Salamander (D. carolinensis). Larvae remain in shallow running water during winter (Desroches and Rodrigue 2004). Abundance of rocks on the stream bed and along the edges of the stream helps protect the young from sub-zero temperatures (Bider and Matte 1994). A constant and sufficient supply of quality water is essential to ensure the availability of overwintering habitats.

Forest canopy and habitat connectivity

The forest canopy is a critical component of Allegheny Mountain Dusky Salamander habitat. Tree cover helps to keep the water cool and well-oxygenated and maintains favourable moisture and temperature conditions for the species on the forest floor (Shealy 1975; Krzysik 1979). Vegetation cover can prevent local erosion and siltation of streams, which could have an adverse effect on water quality and the availability of retreats (Hawkins et al. 1983; Waters 1995; Shannon 2000). By reducing solar radiation and associated drying (Thorson and Svihla 1943), vegetation cover helps to maintain soil moisture and prey abundance, thus improving foraging conditions (Petranka 1998; Grover 2000).

Connectivity among aquatic habitats is important to maintain dispersal, migration, and gene flow, both at the landscape scale (Schalk and Luhring 2010) and at a finer scale (Cecala et al. 2014). In human-disturbed landscapes, salamanders tend to occupy streams that are connected to other watercourses and that have forested riparian areas (Grant et al. 2009). Salamander abundance and movements decrease with forest canopy removal (Spotila 1972; Ash 1997; Ford et al. 2002; Cecala 2012). Restricted movement between streams may cause isolation of populations (Tilley and Scherdtfeger 1981; Grant et al. 2010).

Gaps in the forest canopy act as barriers to the movement of D. quadramaculatus (Cecala et al. 2014). Even small canopy gaps, which have little effect on the physical structure of a stream, can dramatically reduce salamander movements, abundance, and occurrence (Cecala et al. 2014). A canopy gap equivalent to 10 m of channel length reduces D. quadramaculatus movement within streams; gaps larger than 80 m may completely fragment stream populations (Cecala et al. 2014). Given the low probability of recolonization of open-canopy habitats, there is an increased risk of local extinction (Grant et al. 2010; Cecala 2012). Temporary streams that form as a result of heavy rainfall may provide opportunities for dispersal among otherwise terrestrially isolated landscape patches (Schalk and Luhring 2010). As Desmognathus salamanders generally move upstream to lay their eggs and overwinter in retreats where they are protected from freezing (Bishop 1941; Ashton 1976; Snodgrass et al. 2007), access to quality water sources is crucial and requires a certain degree of hydrologic connectivity (e.g., stream branches) in addition to continuous forest cover.

Habitat trends

In the Covey Hill area, forest clearing likely began around the 1830s to permit farming. At the time, cattle had access to nearly the entire area, including residual forests (Bonin 1994). In the mid-1900s, several farms were abandoned, giving rise to a process of old-field succession and re-establishment of forest (Bonin 1994). Farming carried out in the region in the past had impacts on the Allegheny Mountain Salamander habitat locally, including alteration of drainage and flows in some watercourses as well as forest cover changes (Bonin 1993; Sharbel et al. 1995). The type of soil at the top of Covey Hill discouraged agricultural development. The Covey Hill area was not subjected to intensive forest harvesting, presumably because of the topography, and therefore it contains some old forest stands that are unique in the province (Larocque et al. 2006). The habitat appears to have been relatively stable over the past few decades. However, the area is now isolated within a highly fragmented landscape, and the residual habitat is threatened by human activities (Larocque et al. 2006; Frenette 2008).

The Laboratoire Naturel de Covey Hill, a natural research area located on private land, was established in 2006 and harnesses the efforts of research establishments undertaking studies in biology, hydrology, and geomorphology. It has enabled the creation of a network of permanent hydrological measurement stations that support monitoring of Allegheny Mountain Dusky Salamander habitat over the medium and long term (Larocque et al. 2006).

The Niagara area has undergone considerable development in the past couple of centuries, leaving very little suitable habitat for Allegheny Mountain Dusky Salamander (COSEWIC 2007). The species has highly specific requirements for suitable stream habitat, rare in southern Ontario (Markle et al. 2013). Suitable habitat is essentially restricted to the Niagara River Gorge and, possibly, the Niagara Escarpment and the Fonthill Kame Moraine, which may have been connected to the Niagara Gorge in the past (Markle et al. 2013). Habitats outside those areas are heavily urbanized or very fragmented (Markle et al. 2013). Although there is plenty of suitable forested habitat within the gorge, seeps that provide high-quality water are scarce (Markle et al. 2013; W. Weller pers. comm. 2015). The Niagara Escarpment extends from Niagara Falls to Tobermory in southern Ontario; however, it is not known how much suitable habitat it may provide for Allegheny Mountain Dusky Salamander.

The Carolinian population occurs within an unharvested forest stand managed by the Niagara Parks Commission (Yagi and Tervo 2008). The two known habitats of the species in Ontario depend on the discharge of groundwater through rock layers located below the gorge crest. Urban development along the Niagara Gorge has rendered some habitat unsuitable for the species and caused landslides and mudslides in the gorge (Markle et al. 2013). Storm water flows from upstream urbanized areas (roads, parking lots, golf courses) have been discharged over the bank, triggering landslides and inflows of poor quality water (Yagi and Tervo 2008). This type of runoff increases the instability of the steep slopes in the gorge, posing a threat to Allegheny Mountain Dusky Salamander habitat (Yagi and Tervo 2008; Markle et al. 2013). Slumping of seepage areas and landslides may have the potential to create new habitat, but they can also destroy the two streams the species inhabits. In addition, nothing is known about the recharge area for the groundwater springs that feed the two occupied streams (Markle et al. 2013; W. Weller pers. comm. 2015). A single catastrophic event, such as an accidental spill of chemicals or contamination of the spring that feeds one of the seeps, could therefore destroy the species’ habitat in the Niagara Gorge (Yagi and Tervo 2008; Markle et al. 2013).

An incident of that type occurred in April 2016 when construction work 700 m from the Stream 1 locality caused a discharge of several 1000 litres of unsolidified grout into the species’ habitat (M. Karam pers. comm. 2017). Stream 1 is the only stream of the three watercourses in the area that was affected; Stream 2 was not affected (A. Boutin pers. obs.). Tracer dyes allowed a direct link to be established between a well drilled into the rock at the construction site and the water source that supplies Stream 1 (M. Karam pers. comm. 2017). Heavy rainfall following the event caused leaching of part of the grout; most of the grout that settled in the stream, primarily in small depressions and beneath rocks, was removed by hand during subsequent remediation activities (A. Boutin pers. obs.). Rocks were placed along the edge of the stream to provide additional shelter for Allegheny Mountain Dusky Salamander, and cover boards were installed to facilitate future monitoring. During this remediation work, new habitats suitable for the species were identified at Stream 1, upstream from the occupied habitats; however, no individuals were found at these sites (A. Boutin pers. obs.). Although live specimens were observed in June and September following the spill, the impact of the grout spill on the quality and availability of underground retreats, specifically to determine whether they were clogged, could not be evaluated (A. Boutin pers. obs.). In September, just over four months after the event, only small quantities of grout were still visible in the stream (A. Boutin pers. obs.). The long-term effects on the salamanders are unknown.

Among the mitigation measures put in place to prevent further contamination of the habitat during construction work, a water diversion system was implemented on July 29, 2016 (M. Karam pers. comm. 2017). This involved diverting the Stream 1 water source away from the habitat and temporarily supplying it with water from Stream 2. The diversion system was removed upon the completion of the work, on December 16, 2016, before the start of the species’ hibernation period (M. Karam pers. comm. 2017). Despite the alteration of the habitat at Stream 1 in 2016, no information is available to determine the extent of the impact on habitat quality or how much of the habitat was rendered unsuitable for the species. A fine-scale characterization of the two streams where the species occurs at Niagara was conducted following the incident and will support habitat monitoring over time.

In the U.S., Allegheny Mountain Dusky Salamander appears to be persisting within habitat subjected to silvicultural activities and forest fragmentation (Pauley and Watson 2005). In North Carolina, Carolina Mountain Dusky Salamander has been observed in rockface habitats along mountain roads where the bedrock has been dynamited and from which water oozes (Huheey and Brandon 1973). The habitat of some U.S. populations is at risk from “mountaintop removal and valley fill” coal mining (Pauley and Watson 2005). Nearly 500 Appalachian mountaintops have been subjected to this type of mining and have been partly destroyed (van Kote 2009). In the Appalachians, this activity has converted more than 1.1 million hectares of forest to surface mines and has buried 2,000 km of streams (Barton 2011; Bernhardt and Palmer 2011). In 2013, the U.S. Environmental Protection Agency (EPA) estimated that mountaintop removal had destroyed 6.8% of the area of forests that existed in the regions concerned in 1992 (van Kote 2009).

Biology

Little is known about the biology of Allegheny Mountain Dusky Salamander in Canada. Therefore, the information presented in this section is based largely on data from U.S. populations. Extensive descriptions of the biology of D. ochrophaeus in the southern Appalachian Mountains were produced before the recognition of distinct species within the D. ochrophaeus complex. Some inferences can be made from the information available on other members of the species complex because they have similar ecological requirements and lifestyles (Petranka and Smith 2005). In addition, information is available on Northern Dusky Salamander, which occupies similar habitats.

Life cycle and reproduction

The life cycle of Allegheny Mountain Dusky Salamander includes an aquatic larval stage, which extends from hatching to metamorphosis, followed by juvenile and adult stages (Petranka 1998; Pauley and Watson 2005). The juvenile stage (between the larval and adult stages) refers to metamorphosed individuals before they reach sexual maturity (Petranka 1998; Pauley and Watson 2005). Larvae lose their external gills at metamorphosis, and subsequent life stages rely entirely on cutaneous respiration.

Eggs

Allegheny Mountain Dusky Salamander eggs are deposited in clusters in a shallow depression, usually beneath a cover object (Petranka 1998; Pauley and Watson 2005). Some Desmognathus females occupy their nest site 14 to 21 days before oviposition (Forester 1981) and return to the same nest site year after year (Forester 1977). The number of eggs laid is positively correlated with the body size (SVL) of the female (Hall 1977; Keen and Orr 1980). Clutch size varies from 8 – 24 eggs, based on data from the U.S. (Bishop 1941; Pfingsten 1966; Hall 1977). The oviposition period varies geographically across the species’ range, but nests can generally be found throughout the active season, from March to October (Pauley and Watson 2005). In Ohio, egg-laying generally begins in March, peaks in mid-May, and continues into September (Orr 1989). A small proportion of females in Ohio lay their eggs in subterranean refuges at the end of winter and in spring (Keen and Orr 1980). At Covey Hill, ten salamander nests were found in July 2003, but the following year nests were found only in September (Boutin 2003, 2004, unpubl. data). There is only one record of nests at Niagara; a female with eggs was discovered under a cover board at Stream 1 on November 8, 2011 (Weller 2011; NHIC 2015). Three records of nests of Northern Dusky Salamander exist from the Niagara Gorge, on June 23 and 30, 2005 (A. Yagi, unpubl. data). Surveys conducted in June and September 2016 at Stream 1 did not result in observations of Allegheny Mountain Dusky Salamandernests, but two gravid females were observed (A. Boutin pers. obs.). No nests or gravid females were observed at Stream 2 in September 2016 (A. Boutin pers. obs.). The duration of egg development of Allegheny Mountain Dusky Salamander is unclear but is likely similar to that of Northern Dusky Salamander (47.1 ± 17.6 days) (Hom 1987). Desmognathus eggs from North Carolina hatched 50 – 60 days after deposition in the wild; whereas those incubated at 16°C hatched after 71 days (Tilley 1972); the species studied did not include Allegheny Mountain Dusky Salamander, which does not occur in North Carolina.

Parental care

Females of Allegheny Mountain Dusky Salamander remain with their clutches throughout the period of embryo development and through hatching; males do not contribute to parental care (Houck et al. 1985; Petranka 1998). The brooding female defends the eggs from predators, prevents the spread of fungal infestations by eating dead or infected eggs, helps oxygenate the eggs and keep them moist, and reduces yolk layering of the eggs (Tilley 1972; Forester 1979; Forester 1984; Orr 1989). Forester (1979) observed that egg mortality was 47% when the female was present, compared with 100% when the nest was left unattended. Brooding female Desmognathus apparently do not leave the nest to forage, even when disturbed repeatedly, but they feed opportunistically on prey that enter the nest cavity (Organ 1961; Krzysik 1980a; Juterbock 1987). Most females lose weight over the brooding period, using up to 16% of their annual energy budget (Fitzpatrick 1973).

Larval stage

Hatching occurs in fall and spring (Bishop 1943; Keen and Orr 1980; Marcum 1994); however, the precise time of hatching varies within and among populations depending on the elevation and the time of oviposition (Petranka 1998; Pauley and Watson 2005). In Ohio, the majority of larvae hatched from September 14 – October 6, although hatching had also been observed in mid-April (Keen and Orr 1980; Orr 1989). Hatching was observed at Covey Hill on September 17, 2004 (A. Boutin pers. obs.). A young of the year (~17 mm TL) was discovered in Stream 2 in June 2012, suggesting that some larvae hatch in spring at Niagara (Weller 2012).

The duration of the larval period varies depending on the time of oviposition, moisture, temperature, and available food resources (Bishop and Chrisp 1933; Bishop 1941; Keen and Orr 1980; Petranka 1998). Desmognathus larvae develop and metamorphose faster when exposed to higher temperatures and food regimes (Bernardo 1994; Beachy 1995). The gills are usually retained for a few days to several weeks but may persist for 8 to 10 months (Bishop and Chrisp 1933; Bishop 1941). Larvae that metamorphose soon after hatching do not forage and rely on their yolk sac for energy (Orr and Maple 1978; Petranka 1998). They may also feed on small invertebrates captured in the immediate vicinity to the nest (Petranka 1998). Larvae transform into juveniles at 10 to 18 mm SVL (Bishop and Chrisp 1933; Hall 1977; Keen and Orr 1980). Unlike many other species of salamanders, Allegheny Mountain Dusky Salamander larvae do not have to be in the water to survive; larval development only requires substrates that are continuously moist (Bishop and Chrisp 1933; Bishop, 1941).

Sexual Maturity

In Ohio, juveniles grow an average of 7 to 9 mm in SVL/year (Keen and Orr 1980). In New York, males generally reach sexual maturity at three years of age at 37 mm SVL (Hall 1977; Orr 1989). In Ohio, females produce their first clutch of eggs at around 30 to 34 mm SVL at approximately 36 to 42 months of age (Keen and Orr 1980), while in Pennsylvania, the smallest females with mature ova had an SVL of over 31 mm (Hall 1977). While males reach sexual maturity at a smaller size, they surpass females in body size as they age. The significant reduction in growth rate by females after sexual maturity is attained may be due to the major energy investment associated with reproduction, which accounts for nearly 48% of the annual energy budget (Fitzpatrick 1973).

Reproduction

Mating occurs at night during both fall and spring (Bishop 1941; Petranka 1998) and involves an elaborate courtship, involving visual, tactile, and olfactory signals (Uzendoski and Verrell 1993; Evans and Forester 1996; Verrell and Mabry 2000). The courtship includes a stereotypical tail-straddling walk characteristic of all plethodontid salamanders during which the female straddles the male’s tail and pair moves forward and backwards with their tails undulating (Houck et al.1985; Mead and Verrell 2002). Eventually the male deposits a spermatophore on the substrate, which the female draws into her cloaca (Petranka 1998). Females can store viable sperm in the spermatheca for several months (Houck and Schwenk 1984), and sometimes years, as is the case in Northern Dusky Salamander (Marynick 1971). Several Allegheny Mountain Dusky Salamander females studied by Houck and Schwenk (1984) apparently had viable sperm in their spermatheca beyond the mating season, even after ovulation. The phenomenon of multiple insemination, whereby two or more males contribute genomes to the brood of a single female, appears to be possible but is probably rare.

Hibernation

In winter, Allegheny Mountain Dusky Salamanders become less active on the surface and ingest less prey when air temperatures drop to 0 – 5°C (Keen 1979); they remain in underground refugia when the minimum daily temperature drops below 0°C. However, they may remain active during winter around springs, seeps, and bogs (Keen 1979; Green and Pauley 1987). In Ohio, hibernation begins in November and individuals emerge from overwintering sites around the end of March and resume their activities on the surface until October (Orr 1989). In Québec, the hibernation period is presumably longer (Alvo and Bonin 2003).

Demography

The demographic parameters of Canadian populations of Allegheny Mountain Dusky Salamander are not known. Despite strong among-population variability, Desmognathus tend to have a Type I survivorship curve, that is, high survival in early and middle life stages and lower survival in later life (Organ 1961; Danstedt 1975). Survivorship of Northern Dusky Salamander is higher for males than for females and juveniles (Danstedt 1975). The survival rate of non-breeding male Carolina Mountain Salamander (at 0.62) decreases (to 0.40) in the first few years after they reach sexual maturity (Organ 1961). Survivorship appears to be greater in Allegheny Mountain Dusky Salamander than in Northern Dusky Salamander (Hall 1977). Allegheny Mountain Dusky Salamander has an average longevity of seven years (Desroches and Rodrigue 2004), but the upper limit is closer to 15 years (Orr 1989). A Desmognathus specimen in captivity apparently lived for 20 years (Snider and Bowler 1992; Pauley and Watson 2005). Considering that average age at first breeding is 3.5 years and that the oldest breeding individuals in the wild may reach 7 years of age, the species’ generation time is estimated to be 5 years.

Physiology and adaptability

Salamanders in the family Plethodontidae are lungless, and respiration in adults is through their thin and highly vascularized permeable skin (Whitford and Hutchison 1967; Feder 1976; Feder and Burggren 1985). The skin must be moist at all times for gas exchange to occur; however, the skin does not prevent evaporative water loss (Spight 1967, 1968; Spotila 1972; Spotila and Berman 1976; Feder and Burggren 1985). Even in moist terrestrial habitats, these salamanders lose water when they venture outside their retreats or burrows (Feder 1983). Dehydration is more rapid in small individuals, as well as under conditions of lower relative humidity and at elevated temperatures (Spotila 1972). Rehydration occurs in moist habitats, where water can be absorbed through the skin (Shoemaker et al. 1992; Moore and Sievert 2001). As result of these constraints, Allegheny Mountain Dusky Salamander is nocturnal, and its diurnal activities are limited to periods of high humidity and low temperature (Bishop 1941; Holomuzki 1980). Nearly 90% of the surface activity of Desmognathus salamanders takes place between sunset and sunrise (Shealy 1975). Northern Dusky Salamander is mainly active when the air temperature is 14°C – 23°C, and the relative humidity is close to 90% (Ashton 1975). A modest water loss of 3.8% is sufficient to cause Allegheny Mountain Dusky Salamander to abandon foraging and return to a moist retreat (Feder and Londos 1984). Locomotor performance and foraging ability are affected when water loss exceeds 12% of the animal’s body mass (Feder and Londos 1984). Reliance on cutaneous respiration restricts plethodontids to long periods of inactivity interspersed with brief periods of activity during which they can conserve and store energy. Adaptations such as a low metabolic rate and profound resistance to starvation may enable them to survive indefinite periods between unpredictable bouts of feeding (Feder 1983; Feder and Londos 1984). However, if foraging, mate searching, and other social activities are constrained by environmental conditions, dehydration can result in reduction in their condition (Feder and Londos 1984).

Salamanders are sensitive to ultraviolet radiation and to a wide variety of environmental contaminants (see review by Blaustein et al. 2003). The permeable skin of plethodontids provides almost no protection from contamination. Unlike birds, mammals and turtles, which store mercury in feathers, hair, or carapace, respectively, amphibians cannot store heavy metals in body parts away from vital organs (Bank et al. 2007). Allegheny Mountain Dusky Salamander appears to be sensitive to heavy metals and stream acidification (Kucken et al. 1994). Mortality of D. quadramaculatus larvae was observed at pH levels below 4.2. While adults are capable of tolerating a pH of 3.5, larvae will succumb at such conditions (Green and Peloquin 2008). Exposure to acidic conditions could be lethal for Allegheny Mountain Dusky Salamander, which are smaller than D. quadramaculatus. In combination, herbicides, fungicides, and chlorinated hydrocarbons may have detrimental long-term effects on amphibians (Blaustein et al. 2003). Russell et al. (1995) found residues of several pesticides in the body tissues of Spring Peepers (Pseudacris crucifer) from a Canadian national park in southern Ontario 26 years after the application of these products had ceased.

Unlike other plethodontids tested, the skin secretions of Allegheny Mountain Dusky Salamander do not contain chemical substances that would make the salamanders unpalatable to predators. Noxious skin secretions represent an effective antipredator strategy in several salamander species (Brodie 1977; Brodie et al. 1979; Petranka 1998). In some populations, resemblance to toxic species, including species in the genus Plethodon, is viewed as mimicry (aposematic colouration), which helps reduce the risk of predation (Brodie and Howard 1973; Pauley and Watson 2005), including avian predation (Dodd et al. 1974). Allegheny Mountain Dusky Salamander has the ability to self-amputate the tail (autotomy) anywhere along its length; the amputated portion continues to twitch, helping divert the attention of the predator (Petranka 1998). The tail will regenerate and will eventually be fully functional, as described for Northern Dusky Salamander (Mufti and Simpson 2005). Tail autotomy and biting appear to be antipredator behaviours that the salamanders use against snakes, including Common Gartersnake (Thamnophis sirtalis) (Brodie and Howard 1973; Whiteman and Wissinger 1991; Formanowicz and Brodie 1993). Tail autotomy may be an indicator of predation pressure (Danstedt 1975). In Pennsylvania, 7.1% of 404 salamander specimens studied by Hall (1977) showed evidence of tail amputation.

Allegheny Mountain Dusky Salamander differs from other Desmognathus species in that it is relatively tolerant to water loss, which enables it to move a considerable distance from water sources (Houck and Bellis 1972) and occupy drier habitats, farther from water where predation and competition are reduced. The secretiveness of vulnerable stages (brooding females, eggs, and larvae) and their propensity to hide in cryptic habitats represent effective strategies for reducing these threats (Pauley and Watson 2005). Its low metabolic rate, large energy stores, and profound resistance to starvation may enable the species to survive for long periods without food (Feder 1983; Feder and Londos 1984). Allegheny Mountain Dusky Salamander larvae are specially adapted to survive in intermittent streams, temporary habitats where there is only a small amount of surface water or at a minimum saturated ground (Bishop, 1941). This capacity of the larvae, combined with their rapid development, is an adaptation that allows them to develop free from competition and from predation by fish and by other stream salamanders that inhabit permanent streams.

Dispersal and migration

The larvae of plethodontid salamanders have limited swimming ability in their first year of life (Müller 1954; Bruce 1986). They are susceptible to drifting, or passive movement downstream, especially under low temperatures (Bruce 1986; Marvin 2003) or strong currents (Bruce 1986; Lancaster et al. 1996; Elliott 2002). A number of studies have shown an upstream bias in movement among both adults and larvae of stream salamanders, including Northern Dusky Salamander(Lowe 2003; Lowe et al. 2006a; Cecala et al. 2009; Grant et al. 2010). Downstream movement, or drifting, is infrequent and observed on small spatial scales (Lowe 2003; Cecala et al. 2009). These results refute the generally accepted hypothesis that drifting plays an important role in the dispersal of salamanders. Stream salamander movement occurs mainly along stream corridors within the hydrological network, following a model of simple diffusion (Lowe 2003; Lowe et al. 2006b). A study on Northern Dusky Salamanderin undisturbed habitats in Virginia nonetheless revealed a high rate of overland dispersal (out-of-network movement) to adjacent headwater streams (Grant et al. 2010). In that study, larvae showed the greatest probability of dispersing between sections within the same stream network; they also used terrestrial habitats to move outside the network to other branches farther upstream. Juveniles showed lower probabilities of dispersing between stream sections and a non-negligible probability of dispersing overland to an adjacent reach. Post-metamorphic juveniles and adults exhibited the highest site fidelity; adults had dispersal probabilities near zero (Grant et al. 2010).

Movements of Allegheny Mountain Dusky Salamander are not well documented, but data from U.S. populations of this and congeneric species suggest that individuals maintain small home ranges and confine most of their activities close to the streams. In Pennsylvania, the average movement distance recorded over a period of six weeks was 1.8 m (Hall 1977). In Ohio, from May to September, individual Allegheny Mountain Dusky Salamander occupied a home range smaller than 1 m², on average (Holomuzki 1982). Individuals exhibited homing behaviour when displaced 30 m from the point of capture (Holomuzki 1982). These individuals were recaptured in their initial home range 1 – 54 days after displacement (Holomuzki 1982). In North Carolina, the average distance that Desmognathus found on rock faces moved between successive captures was 40 – 45 cm (Huheey and Brandon 1973). Individuals of this species are generally found from 30 – 300 cm from the water (Krzysik 1979), but they may venture across the forest floor a considerable distance from the nearest stream (Bishop 1941). In U.S. populations, the average home range of Northern Dusky Salamanderis estimated to extend not further than 15 m from a stream or seep (Petranka 1998). Females moved upstream and nested near the terminus of headwater streams (Snodgrass et al. 2007). This strategy may minimize the exposure of eggs and larvae to predatory fish, high current velocities, and/or deteriorating water quality (Forester 1977; Bruce 1986). During oviposition, Northern Dusky Salamandermay use depths exceeding 1 m beneath interstices in the stream bed (Ashton 1975), which may also be the case for Allegheny Mountain Dusky Salamander.

With the approach of winter, Allegheny Mountain Dusky Salamander undertakes seasonal migrations (Pauley and Watson 2005) to suitable underground refugia (Keen 1979). It is very likely that the species moves upstream to overwinter near springs in underground refuges protected from sub-zero temperatures, as is the case with Northern Dusky Salamander(Ashton 1976).

Owing to its susceptibility to desiccation, Allegheny Mountain Dusky Salamander has a limited ability to disperse overland. Heavy rains can create temporary streams, allowing salamanders to colonize new habitats. Grover and Wilbur (2002) found that Northern Dusky Salamanderremained in artificial seepage areas created 3 – 5 m from streams.

Interspecific interactions

Prey

Allegheny Mountain Dusky Salamander is a generalist forager and feeds on a wide variety of invertebrates, primarily insects and their larvae, which it ambushes (Krzysik 1980b; Petranka 1998). Lepidopterans and dipterans are the most important prey items, although its diet also includes ants, crane flies, homopterans, hymenopterans, spiders, mites, phalangids, and millipedes (Bishop 1941; Fitzpatrick 1973; Petranka 1998). Foraging is positively correlated with precipitation and decreases when the daytime temperature is lower than 5°C (Keen 1979).

Predation and competition

Carabid beetles, crayfish, snakes, small mammals, and birds are known to prey on Allegheny Mountain Dusky Salamanders. Northern Watersnake (Nerodia sipedon), Common Gartersnake, and Ring-necked Snake (Diadophis punctatus) feed on salamanders and their eggs (Uhler et al.1939; Hom 1987; Whiteman and Wissinger 1991; Desroches and Rodrigue 2004). Short-tailed Shrew (Blarina brevicaudata), whose burrows are used by a large variety of salamanders, is a known predator of the species (Brodie et al. 1979), as are Raccoon (Procyon lotor), Opossum (Didelphis virginiana), Striped Skunk (Mephitis mephitis), and various small rodents (Petranka 1998; Pauley and Watson 2005). Avian predators include Hermit Thrush (Catharus guttatus), which uncovers salamanders during diurnal foraging (Bishop 1941; Petranka 1998). Spring Salamander (G. porphyriticus) is a major predator of Allegheny Mountain Dusky Salamander (Formanowicz and Brodie 1993; Uzendoski et al. 1993; Hileman and Brodie 1994) and consumes small co-occurring stream salamanders along with their larvae and eggs (Bishop 1941; Bruce 1972, 1979; Petranka 1998). Predation by large aquatic salamanders may have played an important role in the evolution of terrestrialism in small-bodied Desmognathus (Hairston 1986, 1987). Brook Trout (Salvelinus fontinalis) is also a known predator of salamanders (Lowe et al. 2004; Barr and Babbitt 2007). The presence of fish influences stream salamander larval density and development (Petranka 1983; Sih et al. 1992; Barr and Babbitt 2002; Lowe and Bolger 2002). Predation may be responsible for the low reproductive success of Northern Dusky Salamander(Hom 1987).Allegheny Mountain Dusky Salamander avoids aquatic predators by using habitats farther from the water and habitats where fish are absent (Boutin, unpubl. data). The salamanders can defend their eggs against conspecifics and carabid beetles but not against larger predators (Forester 1979; Hom 1987). Adults occasionally cannibalize eggs, larvae, and juveniles (Fitzpatrick 1973; Wood and Wood 1955).

Dusky salamanders avoid chemical signals left on the ground by injured conspecific salamanders, by other salamander species, and by certain predators such as Ring-necked Snake (Cupp 1994; Luttershmidt et al. 1994). In response to a predator, Allegheny Mountain Dusky Salamander may remain immobile, blending in with its surroundings (Dodd 1990), flee quickly, or adopt postures in which the body and tail writhe violently (Bishop 1941; Whiteman and Wissinger 1991).

The ecology of Allegheny Mountain Dusky Salamander is greatly influenced by interspecific interactions with other salamanders (see also Habitat Requirements: Habitat use in relation to other salamanders). In regions of sympatry, salamanders segregate along a moisture gradient that minimizes niche overlap (Hairston 1987; Grover 2000; Grover and Wilbur 2002; Petranka and Smith 2005; Boutin 2006). In stream salamander communities, like the one at Covey Hill, Spring Salamander is usually the most aquatic species, as well as a strong predator and competitor (Forester 1979; Petranka 1998). It successfully displaces Northern Dusky Salamandertowards drier, less optimal microhabitats (Grover 2000), and Northern Dusky Salamander, in turn, is able to displace Allegheny Mountain Dusky Salamander towards drier habitats that are farther from water and have finer substrates than the optimal habitats it uses when alone (Krzysik 1979; Grover and Wilbur 2002). In areas of sympatry, avoidance of competition between the larvae of Allegheny Mountain Dusky Salamander and Northern Dusky Salamander may be associated with differences in hatching times and in yolk absorption times (Orr and Maple 1978). Although Allegheny Mountain Dusky Salamander has specific habitat requirements, it is able to use a greater diversity of microhabitats than Northern Dusky Salamander(Krzysik 1979).

Hybridization

Although Allegheny Mountain Dusky Salamander and Northern Dusky Salamander are generally sexually incompatible (Verrell 1990, 1994), they hybridize occasionally in areas of contact in Ohio, Pennsylvania, and Québec (Karlin and Guttman 1981, 1986; Houck et al. 1988; Sharbel et al. 1995). Hybridization is infrequent, and backcrossing with Allegheny Mountain Dusky Salamander is apparent in most hybrids (Sharbel et al. 1995; Boutin 2006).

Parasites and diseases

Allegheny Mountain Dusky Salamander may be parasitized by protozoans, larval and adult nematodes, trematodes, cestodes, and acanthocephalans (Rankin 1937; Baker 1987; Goater et al. 1987). Chytridiomycosisand infections caused by viruses in the genus Ranavirus are emerging pathologies that pose a serious threat to amphibians. Chytridiomycosis has been detected in 88 salamander species (Olson and Ronnenberg 2014), including D. aeneus, D. apalachicolae, D. conanti, D. fuscus, D. marmoratus, D. monticola, D. ocoee and D. quadramaculatus (Bd-Maps 2015). Ranavirus was detected in five species of Desmognathus in a protected southern Appalachian watershed at a prevalence rate of 30.4% (n=92, 95%, 21.3–40.9%; Rothermel et al. 2013). In Canada and elsewhere, no cases of either of these pathologies have been reported for Allegheny Mountain Dusky Salamander. As of December 2017, the emerging salamander chytrid fungus, Batracochytrium salamandrivorans, has not been recorded from North America.

Population sizes and trends

Sampling effort and methods

A great deal of effort has been devoted to searching for dusky salamanders in Canada (see Search Effort). Stream salamander surveys conducted since the preparation of the previous status report for this species have further delineated the distribution of Allegheny Mountain Dusky Salamander in Québec and Ontario. Nonetheless, the available data are inadequate for assessing the Canadian population trend. As intermittent streams and seepage areas potentially used by Allegheny Mountain Dusky Salamander cannot always be seen on topographic maps and aerial photos, sampling must be carried out by walking through the habitats. In Québec, the habitats are located mainly on privately owned land, and authorizations must be obtained from several landowners in advance of surveys. In Ontario, the habitats are located in steep and treacherous terrain, which makes them fairly inaccessible and complicates fieldwork. Furthermore, the salamanders hide in underground burrows or refuges, making it difficult to assess abundance.

In Québec, surveys conducted within the known range of Allegheny Mountain Dusky Salamander have been aimed mainly at detecting the species’ presence at known sites and in potential habitat that has not previously been explored. Catch-per-unit effort (CPUE) results are increasingly being documented, but the area covered in the surveys is not always available (BORAQ 2015). Since 2008, the presence of Allegheny Mountain Dusky Salamander has been monitored annually at 10 stations distributed along 9 streams at Covey Hill (Environment Canada 2014; N. Tessier pers. comm. 2015).

The primary objective of the sampling activities in Ontario was to detect the species’ presence along the Niagara Gorge. In 2005, 19 individuals from the Stream 1 locality were marked in an attempt to evaluate the population size (A. Yagi, unpubl. data). Known sites were visited several times on behalf of the Ontario Ministry of Natural Resources and Forestry and by Ontario Power Generation.

Abundance

The size of Allegheny Mountain Dusky Salamander populations in Canada is unknown. At Covey Hill, in the 1990s, nearly 120 individuals and 12 D. ochrophaeus x D. fuscus hybrids were found in 5 temporary streams and 2 seeps (Bonin 1993). The densities (excluding hybrids) in three temporary streams varied from 0.67 – 1.19 individuals/m² (Bonin 1993; Sharbel et al. 1995). Active searching (based on a maximum effort of 1 hour) conducted in stream sections 25 m long and 0.5 m – 1 m wide resulted in the capture of up to 7 adults/survey, which corresponds to a maximum density of 0.28 – 0.56 adults/m² (A. Boutin, unpubl. data). At the 10 stations monitored annually by the MFFP, which were selected on the basis of Allegheny Mountain Dusky Salamander abundance, 0 – 24 adults/station were captured (average of 5.5, n=82), for a total search effort of 24 – 60 minutes (average of 41 min; n=50) (L. Bouthillier, unpubl. data). In the U.S., Allegheny Mountain Dusky Salamander densities range from 0.96 – 1.20 individuals/m² in optimal habitats in Ohio (Orr 1989) and from 0.62 –to 1.07 individuals/m² in a stream in Pennsylvania (Hall 1977). The total Appalachian population probably numbers approximately 1000 mature individuals, but no accurate estimates exist. Because the detection probability is likely low, the number of individuals is presumably underestimated when based solely on captures.

In Ontario, the species is considered to be very rare owing to its extremely restricted distribution. In 2013, 40 records of Allegheny Mountain Dusky Salamander were documented in the Niagara population, including 17 from the new Stream 2 locality (NHIC 2015). In 2016, 17 new records were added, 15 of them from Stream 1 (A. Boutin, unpubl. data). In 2005, an effort was made to estimate the size of the Niagara population at Stream 1 (A. Yagi, unpubl. data). The preliminary results suggest a rough population estimate of at most 33 mature individuals, with a recapture rate of 52.6% (n=19; A. Yagi, unpubl. data). The mark-recapture study has not been repeated. The data available prior to 2013 indicate that 1 – 2 individuals (average of 1.2) were found per visit (n=19) at Stream 1 (NHIC 2015), and 1 – 6 individuals (average of 2.4) at Stream 2/visit (n=7) (NHIC, 2015). Densities and CPUE cannot be assessed with the available data (Markle et al. 2013; NHIC 2015). In June 2016, 10 Allegheny Mountain Dusky Salamanders were found for a total search effort of 5.35 h; in September of the same year, 5 individuals were observed, for a total effort of 5.58 h (A. Boutin, unpubl. data). At Stream 2, 2.73 h of active searching in September 2016 led to the observation of two specimens in known habitats (A. Boutin, unpubl. data). At both localities, cover boards previously installed for monitoring purposes were still being used by the species (A. Boutin pers. obs.). The total Carolinian population probably numbers less than 100 mature individuals, but no accurate estimates exist.

Considering the species’ extremely restricted distribution in Canada and the considerable searching carried out in suitable habitats, it appears that the rarity of the Allegheny Mountain Dusky Salamander is attributable to the scarcity of suitable specialized habitat.

Fluctuations and trends

With the data available in Canada, it is not possible to evaluate population trends or multi-year fluctuations. At Covey Hill, a comparison of historical and recent data suggests that the species has persisted at the known sites since 1990 (BORAQ 2015). Only 3 of 10 historical records (i.e., from before 1995) have not been validated recently, either because the sites have not been visited or because the species has not been observed there since that time (C. Laurendeau pers. comm. 2015). The presence of gravid females, nests, and larvae is indicative of reproductive success (A. Boutin unpubl. data). Annual monitoring at two stations suggests that the species has persisted locally at least since 2008 (L. Bouthillier unpubl. data; Environment Canada 2014), but no inferences about population trends can be made due to small sample sizes. In the future, the plan is to monitor occurrences with standard methods that would allow the detection of population trends in the medium and long term (Équipe de rétablissement des salamandres de ruisseaux, in prep.).

At Niagara Gorge, the discovery of a second locality in 2010 increased the known extent of occurrence of the species in Ontario. This increase is indicative of stepped-up search efforts rather than of population growth or the establishment of a new subpopulation. Despite the small number of individuals observed, all life stages are represented there (i.e., adults, juveniles, larvae, and eggs; Markle et al. 2013; NHIC 2015). Researchers plan to gather more information about population sizes and trends in the future (Markle et al. 2013).

Globally, the species’ conservation status is apparently stable or expected to decline slightly in the short term, whereas in the long term it should be fairly stable in terms of extent of occurrence, area of occupancy, and population size (NatureServe 2015). Isolated populations, such as those at Covey Hill and Niagara Gorge, nonetheless, require special attention (Petranka 1998; NatureServe 2015).

Rescue effect

Owing to the species’ limited dispersal capacity, there is no possibility of individuals of Allegheny Mountain Dusky Salamander being able to disperse across the U.S. - Canada border. Contacts between the Covey Hill population and the closest population in New York State, which is about 12 km away, are unlikely, and agriculture, logging, and construction of access roads have modified the habitat adjacent to Covey Hill and reduced habitat connectivity. The populations in New York State are separated by geographic distance from the Niagara Gorge populations and physically separated by the Niagara River, which acts as a barrier to dispersal for Allegheny Mountain Dusky Salamander (Markle et al. 2013). As a result, there is little or no rescue potential for the Canadian populations from the U.S. in the event of a decline or extirpation. In the event of an extreme situation, the populations in New York State could nonetheless be a potential source of specimens, provided these salamanders have adaptations enabling them to survive in our climate and provided that sufficient suitable habitat is available to sustain them.

Threats and limiting factors

Threats

The IUCN Threats Calculator was applied to the two populations of Allegheny Mountain Salamander by a panel of experts (Appendices 5 and 6). The overall threat impact was deemed to be “high - medium” for the Appalachian population and “very high” for the Carolinian population. For the Appalachian population, the greatest threats (each with impact score of “medium – low”) were deemed to be from (i) logging and wood harvesting (Biological resource use), (ii) dams and water management (Natural system modifications), and (iii) agricultural and forestry effluents (Pollution). For the Carolinian population, the greatest threats were deemed to be from (i) dams and water management and habitat modification by invasive Common Reed (Natural system modifications), and (ii) landslides (Geological events) (each with impact score of “high”), followed by (iii) industrial effluents and other sources of contamination (Pollution with impact score of high - medium). In addition, increased frequency and intensity of droughts and storms and flooding associated with climate change threaten both populations, but the impacts and time-frames are largely unknown. The threats determined to apply are discussed below in their perceived order of importance.

Dams and water management/use

In Canada, Allegheny Mountain Dusky Salamander habitats are fed by groundwater springs that are critical to reproductive success and the survival of eggs and larvae, and that provide crucial areas for egg laying, foraging, rehydration, and hibernation. Declines in stream salamanders have been linked to lowering of the water table and to a reduction in dissolved oxygen concentrations (Bowles and Arsuffi 1993; Turner 2004).

Appalachian population

At Covey Hill, the water table supplies water to a large proportion of the area of occupancy of Allegheny Mountain Dusky Salamander (Environment Canada 2014). It is also the only source of drinking water for the municipalities of Franklin and Havelock (Frenette 2008). The geologic formation characterizing this hill and the large peat bog there serve as an important water reservoir and help to maintain the groundwater reserves for the entire area (Barrington et al. 1993; Larocque et al. 2013). Encompassing an area of 70 ha, the Covey Hill peat bog is located on three privately owned parcels of land, one of which now belongs to the Nature Conservancy of Canada (Environment Canada 2014). Alteration of the peat bog could have disastrous consequences for the species. However, pursuant to the Environment Quality Act (CQLR, c. Q-2), this habitat may not be altered without a certificate of authorization. In the early 2000s, one landowner transformed a portion of the peat bog into a lake with the intention of stocking it with trout (Environment Canada 2014).

Water withdrawals from the Covey Hill groundwater reserves are made by few food processing companies, apple orchards, and nearby dwellings for domestic use (Larocque et al. 2013). Some dwellings, orchards, and a campground located at the base of a site occupied by the species undoubtedly use a considerable amount of water; however, water consumption in the region was not considered a threat to the groundwater source in the early 1990s (Barrington et al. 1993; Alvo and Bonin 2003). The situation has not been re-evaluated, even though demand has changed (Environment Canada 2014). Additional large-scale development on the hill entailing the construction of new drinking water wells could compromise the groundwater reserves (Alvo and Bonin 2003; Environment Canada 2014). Increased groundwater extraction is likely to cause lowering of the water table that supplies water to the habitats of Allegheny Mountain Dusky Salamander (Barrington et al. 1993; Jutras 2003) and could alter the natural fluctuations in the hydrologic regime (Jutras 2003; Frenette 2008). It is not known what level of water extraction, from all activities combined, would be considered acceptable for the long-term maintenance of the aquifer’s recharge capacity and of the Allegheny Mountain Dusky Salamander population (Deland and Sierra 2016). The expected consequences of a decrease in water availability include habitat loss and fragmentation, isolation of salamanders in residual habitat and mortalities due to the salamanders’ limited dispersal abilities (Environment Canada 2014).

The groundwater resource is of exceptional quality and has already attracted the attention of proponents of spring water bottling projects (Frenette 2008). Over the past decades, project proposals for groundwater extraction for both commercial and industrial use were put forward on a regular basis (COSEWIC 2007). A bottling project proposed at Franklin was turned down due to opposition by the local community (Bonin 2000). A hydrogeological study done in 2004 in the municipality of Franklin showed that groundwater extraction for bottling purposes is feasible but would create conflicts among existing groundwater users (Environment Canada 2014). It is believed that local or regional overexploitation of groundwater could have irreversible impacts (Côté et al. 2006). The situation is further complicated by the fact that the groundwater at Covey Hill is shared with the United States. The municipality of Havelock and possibly that of Franklin have passed bylaws prohibiting groundwater extraction for bottling purposes (C. Deland pers. comm. 2015).

The increased use of water for agriculture remains a major threat to the habitat of Allegheny Mountain Dusky Salamander (C. Deland pers. comm. 2015). Drainage of the forest environment in maple stands and excessive pumping of water for agriculture at Covey Hill poses a very high risk (Deland and Sierra 2016). The existing standards and practices related to forest and agricultural drainage need to be documented, along with their impacts in terms of stream siltation and groundwater levels (Deland and Sierra 2016). An increase in the volumes of water used by the stone quarrying operation on the hill also represents a potential concern (C. Deland pers. comm. 2015).

Water control structures and roads affect the viability of populations because they alter watershed connectivity and reduce the movements of salamanders (Schalk and Luhring 2010). Dams are present on Covey Hill, some of which are documented (Centre d’expertise hydrique 2015), but it is not known to what extent they control water levels and affect the species’ movements. A sudden inrush of water in 2003 caused the water level in a stream to rise dramatically in the space of a few minutes, submerging the terrestrial habitats adjacent to the stream bed (A. Boutin pers. obs.). Such events, which are likely caused by water released from a dam, have the potential to flood dusky salamander nests and carry off the occupants.

Carolinian population

In Ontario, the two streams inhabited by Allegheny Mountain Dusky Salamander are fed by different sources whose recharge zones have not yet been fully delineated through appropriate hydrological studies. This situation makes conservation more complex (Yagi and Tervo 2008; Markle et al. 2013). Work was undertaken to determine the relationship between the water level in the generating station reservoir, which is managed by Ontario Power Generation (OPG), and streamflow at the Stream 1 and Stream 2 sites (Thompson et al. 2012, 2014). Results suggest that the water flowing in Stream 2 does not come from the reservoir, it does not fluctuate with the water levels in the reservoir and continued to fluctuate when the reservoir was dewatered in 2011 (Thompson et al. 2012, 2014; W. Weller pers. comm. 2015). However, the SAB I forebay appears to be positively correlated to the fluctuations in the Stream 2 flow (Thompson et al. 2012, 2014). The groundwater recharge area that supplies water to the Stream 1 site has not yet been identified but was shown not to be the OPG reservoir (Thompson et al. 2012, 2014). A link between the stream and a well drilled about 700 m from the site was nonetheless established in 2016 (A. Boutin, unpubl. data). The discharge in Stream 1 is not affected by OPG operations and the majority of the large variations in the flow can be explained by precipitation (Thompson et al. 2012, 2014; W. Weller pers. comm. 2015), which suggests that rainfall and storm water runoff play an important role in groundwater recharge.

Although current groundwater levels in the Niagara Gorge are adequate to sustain the existing Allegheny Mountain Dusky Salamander population, any decrease, curtailment, or interruption of the groundwater supply is considered a serious threat to the continuing existence of these salamanders (Markle et al. 2013). Therefore, any large-scale development at the top of the Gorge or on adjacent land could affect the quality and quantity of the water source that sustains the species’ habitat. Any such development could potentially increase or decrease peak flows and discharge volumes, and increase sedimentation, turbidity, and water temperatures (Markle et al. 2013).

Agricultural and forestry effluents

Canadian populations of Allegheny Mountain Salamander are at risk from groundwater and surface water contamination. Runoff from farmland and pastureland may contain contaminants with potentially adverse effects on the salamanders (Wilson and Dorcas 2003). Nitrogen is abundant in agricultural and urban watersheds; it is one of the contaminants that poses the greatest threat to the survival of amphibians (Rouse et al. 1999). These negative impacts are numerous (reviewed by Rouse et al. 1999) and can affect amphibian development at levels between and above 2 and 5 mg/L. More than 15 years ago, nearly 20% of the surface water samples taken near the Great Lakes in Ontario and the United States (n=8,545) had nitrogen levels greater than 3 mg/L, and 3% of them had levels exceeding 10 mg/L (Rouse et al. 1999). An organochlorine insecticide has been reported to have an adverse effect on the reproductive success of Red-spotted Newt (Notophthalamus viridescens) (Park et al. 2001).

Appalachian population

Although part of the Covey Hill peat bog is protected at present, this protection does not prevent contamination of the water. At Covey Hill, most of the habitats of Allegheny Mountain Dusky Salamander are at higher elevations than much of the farmland and development, which may prevent contamination to some extent. However, the pesticides and fertilizer used on agricultural land and adjacent golf courses have the potential to contaminate groundwater sources. The use of certain pesticides, notably in apple growing, has been identified as a major threat at the Covey Hill site (Deland and Sierra 2016). It is not known what effect the chemical constituents of pest control products have on water quality at Covey Hill or the tolerance of Allegheny Mountain Dusky Salamanders to those substances (Deland and Sierra 2016). However, CNC (2015) concluded that 64% of the pesticides used in the Covey Hill area could have a moderate effect on the environment. This threat could increase significantly if agricultural development occurs upstream of the Covey Hill site.

Carolinian population

Water quality at the two occupied streams has not been tested in recent years in the Niagara Gorge area, but there is potential for contamination from agricultural effluents. The threat was scored as unknown for this population.

Household sewage and urban wastewater, industrial effluents

These sources of contamination pose a threat for the Carolinian population but are scored as unknown for the Appalachian population. In the Niagara area, storm runoff from urban and industrial areas at the top of the gorge represents a major source of contamination (Yagi and Tervo 2008; Markle et al. 2013). Little is known about the recharge area and the travel route of the water that supplies the Stream 1 and Stream 2 salamander localities, but the risk of contamination is high. As observed in 2016, accidental contamination associated with human activities has the potential to destroy salamander habitats even if they are carried out at a certain distance from known localities of Allegheny Mountain Salamander (see Habitat Trends). Inputs of fertilizers or herbicides, sediments, dissolved solids, or a change in water temperature or pH could reduce dissolved oxygen levels critical to the species’ persistence (Markle et al. 2013). The large volumes of storm water discharged into the gorge may contain many chemicals and other pollutants, heavy metals, oils, and hydrocarbons (Markle et al. 2013), which can have adverse effects on salamanders and interfere with their reproductive success (Blaustein et al. 2003). In the St. Lawrence River (Québec) and the Ottawa River, hydrocarbons have caused hormonal disruptions in Mudpuppy (Necturus maculosus), which could potentially affect its reproduction (Gendron et al. 1997). Northern Dusky Salamander avoids nesting in streams that receive runoff from residential areas and the potential for increased erosion there (Snodgrass et al. 2007).

Air pollutants

First-order streams are susceptible to contamination caused by the deposition of airborne pollutants (Fitzgerald et al. 1991; Bank et al. 2006) and have low acid neutralizing capacities (Green and Peloquin 2008). Plethodontids are sensitive to heavy metal contamination (Bank et al. 2007), as well as to soil and water acidification (Roudebush 1988; Wyman 1988; Kucken et al. 1994). Contaminants transported atmospherically have the potential to affect amphibians in remote, relatively undisturbed environments, and even low levels of these contaminants can have toxic effects (Blaustein et al. 2003). A 50% reduction in Allegheny Mountain Dusky Salamander abundance was observed in streams showing signs of acidification and heavy metal contamination (Kucken et al. 1994). Atmospheric deposition is believed to be the primary source of the mercury (Hg) found in surface waters in the northern United States (Fitzgerald et al. 1991). Mercury accumulation in Acadia National Park, a protected area in Maine where Northern Dusky Salamander has experienced a significant population decline, likely reflects deposition of mercury from upwind sources (Bank et al. 2006). Negative impacts of water acidification have been demonstrated in D. quadramaculatus, a large salamander species (Green and Peloquin 2008) and could prove to be particularly lethal for Allegheny Mountain Dusky Salamander, which is smaller. The Covey Hill and Niagara Gorge streams have not been studied with a view to determining if they are currently undergoing acidification, and this threat was scored as unknown for both Canadian populations.

Garbage and solid waste

This source is a threat primarily for the Carolinian population. In 2016, a large area of accumulated waste was noted in the habitat of Allegheny Mountain Dusky Salamander at Stream 2 (A. Boutin pers. obs.). Probably due to the topography of the site, garbage thrown from the road that runs along the top of the escarpment accumulates at the base of a rock wall adjacent to the stream occupied by the species. The accumulated waste consisted of debris of all sorts, including construction material, paint containers and refuse such as containers, packaging, plastic bags, cans, and bottles. Although this threat is localized, the species’ habitat could become contaminated as a result of the release of hazardous products, such as gasoline, oils, and solvents.

Logging and wood harvesting

Logging and wood harvesting was identified as a threat for the Appalachian population. A number of studies have described the adverse and potentially severe effects of timber harvesting on salamanders (Corn and Bury 1989; Petranka 1994; Gibbs 1998). Salamander abundance decreases with a reduction in forest cover, even in heavily forested watersheds (Cecala 2012). Over the long term, the abundance of Desmognathus decreased with increasing volume/ha of timber removed (Moseley et al. 2008). Gravid females of Allegheny Mountain Dusky Salamander were found to weigh less in cut treatments (Knapp et al. 2003). Since clutch size is directly linked to body size, forest clearing can have an impact on reproductive success and survival. Mean Desmognathus density was 30% higher in streams within mature second-growth forests that had remained undisturbed for 90 years than in streams located in disturbed forests (Moseley et al. 2008). Forest canopy removal not only affects moisture and temperature conditions critical to the survival of plethodontids, but it also reduces water quality (Shealy 1975; Krzysik 1979; Jung et al. 2000). In addition, plethodontids are particularly vulnerable to edge effects such as habitat drying and warming that are associated with forestry operations, including forest harvesting and road construction (deMaynadier and Hunter 1998; Gibbs 1998). Soil compaction, erosion, sedimentation and habitat warming compromise the quality and availability of retreats for egg laying, resting, rehydration, and hibernation (Alvo and Bonin 2003; Trottier 2006). In addition, reduction in leaf litter and increased soil temperatures limit salamanders’ burrowing and foraging capacity and reduce prey abundance (Feder 1983; Jaeger et al.1995). Sedimentation is a threat to the integrity of small stream ecosystems (Lowe et al. 2004) and can greatly reduce salamander abundance (Welsh and Olliver 1998; Lowe and Bolger 2002; Lowe et al. 2004). The infusion of fine sediments associated with silvicultural activities increases siltation in streams and fills in interstitial spaces that salamanders use for foraging, shelter, rehydration, oviposition, and hibernation (Hawkins et al. 1983; Waters 1995; Shannon 2000). As these refuges are lost, protective cover from predators is reduced or eliminated, which can result in increased mortality (Lowe and Bolger 2002; Lowe et al. 2004). In addition, the loss of cover and retreats can increase competition and predation pressures and cause shifts in stream salamander communities (Krzysik, 1979; Southerland 1986a,b,c; Roudebush and Taylor 1987). Terrestrial habits of Allegheny Mountain Dusky Salamander may help to reduce these impacts; however, in a context where forest habitats are drying, the availability of moist refuges in streams is critical, and competition for these habitats may become significant.

At Covey Hill, current silvicultural activities mainly affect the lowland areas around the hill. The area of occupancy of Allegheny Mountain Dusky Salamander consists entirely of privately owned land that is not protected from timber harvesting (Jutras 2003). Covey Hill contains some old forest stands unique in the province (Larocque et al. 2006) and which constitute one of the only remaining tracts of forest in the region (Deland and Sierra 2016). Owing to their age and composition, these high-quality stands are of interest to logging companies (S. Giguère pers. comm. 2016) and at high risk for forest harvesting (Deland and Sierra 2016). The municipalities of Franklin and Havelock currently have no tree-cutting bylaws (Environment Canada 2014), which means that landowners can harvest as many trees as they want. Logging remains a particularly critical threat to intermittent streams and seepages, which are the species’ main habitat in Québec (Alvo and Bonin 2003; Jutras 2003; Trottier 2006). In the event of extensive forest harvesting operations, the use of heavy machinery poses a high risk to the habitat of the Allegheny Mountain Dusky Salamander (Deland and Sierra 2016).

In the Niagara Gorge, the entire extent of habitat suitable for the species is on land owned and managed by the Niagara Parks Commission, and timber harvesting is not a significant threat (Yagi and Tervo 2008). Although it rules out the development or clearing of forested land, tree removal may occur accidentally or through a natural event such as a mudslide (Markle et al. 2013).

Residential and commercial development

Stream salamanders are sensitive to large-scale (i.e., landscape) habitat alterations that change the spatial configuration of stream networks and reduce their connectivity (Welsh and Ollivier 1998; Lowe and Bolger 2002; Grant et al. 2009). Roads affect the viability of populations because they alter watershed connectivity and reduce the movements of salamanders (Marsh et al. 2004; Schalk and Luhring 2010). Over the long term, Northern Dusky Salamander may disappear completely from urbanized watersheds (Price et al. 2012; Scheffers and Paszkowski 2012).

In areas that are heavily urbanized or characterized by extensive agricultural use, small streams are lost and stream networks become simplified over time (Dunne and Leopold 1978; Sophocleous 2000). Such changes could be detrimental to Allegheny Mountain Dusky Salamander, which occupies small headwater streams, needs access to streamside habitat for egg laying and hibernation, and is incapable of long-distance dispersal outside the hydrological network. Loss of stream connectivity reduces the likelihood of recolonization of streams through overland movement (Fagan et al. 2009); overland dispersal can greatly reduce isolation and risk of extirpation (Lowe 2002). This could be a serious threat at Covey Hill, particularly if the watershed undergoes development in the future. Few measures have been implemented to apply the Protection Policy for Lakeshores, Riverbanks, Littoral Zones, and Floodplains (Q-2, r.35) under the Environment Quality Act mentioned in the land-use plan of the Haut-Saint-Laurent MRC. Given that only the main streams on Covey Hill have been mapped, alteration of streams and riparian buffer strips is a priority threat for which the level of concern and risk are high (Deland and Sierra 2016). In the Niagara Gorge, the two streams inhabited by the species are isolated from each other, and it is most unlikely for the species to naturally move between the two sites (Markle et al. 2013).

Appalachian population

The agricultural zoning of Covey Hill greatly constrains the potential for urban development (C. Deland pers. comm. 2015), and this threat was scored as low impact. At present, most of the developed areas at Covey Hill are located in the lowlands, downstream from the Allegheny Mountain Dusky Salamander habitat. A proposal to build a golf course there was studied in 1990, and many cottages were built (COSEWIC 2007). At Covey Hill, crop, livestock, and maple syrup production represent the main threats to the species’ habitat, along with resort development, to a lesser extent (C. Deland pers. comm. 2015). The desire to maintain agricultural land use and concern about disturbance associated with certain projects have led to citizen opposition to the development of tourism infrastructure (Deland and Sierra 2016).

Carolinian population

At the Niagara Gorge site, the salamander population is threatened by urban and industrial development on the tablelands above the gorge (Yagi and Tervo 2008; Markle et al. 2013); however, the direct threat from these sources was scored as negligible because the effects are mainly through hydrological changes and contamination, which are addressed in other threat categories. In urbanized areas, Desmognathus salamanders are present at lower densities and have disappeared from a number of watersheds due to intensive urban and agricultural development (Orser and Shure 1972; Wilson and Dorcas 2003; Price et al. 2006). Urban development has impacts on hydrology and geomorphology, as well as on riparian ecosystem function and structure (Grant et al. 2009), and it increases the risk of extinction events (Price et al. 2006). Watershed urbanization increases runoff from paved surfaces and reduces the stability of surrounding land (Welsh and Olliver 1998; Lowe and Bolger 2002; Lowe et al. 2004). Contaminants, fine sediments, and organic matter from urban and agricultural areas alter the food chain and ultimately reduce salamander growth, reproduction, and survival (Barrett et al. 2010). Urban development has caused a 30% decline in Northern Dusky Salamander populations over a period of some 30 years and has led to local extinctions in 71 small watersheds (Price et al. 2006). Furthermore, in highly disturbed watersheds, maintaining riparian buffers may not lessen the impacts of upland watershed development on stream salamanders (Wilson and Dorcas 2003). Riparian buffers may therefore be insufficient to protect local populations (Wilson and Dorcas 2003). In the Niagara Gorge, urban development of the upstream area or development located near springs that supply water to the species’ habitat could exacerbate the factors that already pose a threat to the habitat of Allegheny Mountain Dusky Salamander.

Invasive, non-native/alien species

Dense patches of the invasive strain of European Common Reed (Phragmites australis) have become established at the base of the Niagara Gorge along gently sloping sections of the bed of some streams, including Stream 1 (Markle et al. 2013; A. Boutin unpubl. data). Although the OMNRF has implemented certain measures to control European Common Reed at the Stream 1 locality, it has already eliminated potential habitat for Allegheny Mountain Dusky Salamander and could eventually colonize upstream habitats occupied by the species (Markle et al. 2013; A. Yagi pers. comm. 2015). In June 2016, a new European Common Reed colony, covering approximately 3 m², was found at the base of the cliff above where the spring that feeds Stream 1 bursts out of the rock face (A. Boutin pers. obs.). The main impact of European Common Reed invasion of streams is to choke the stream bed with vegetation and to modify flow (Groupe Phragmites 2012); therefore, the spread of this plant poses a serious threat to the species’ habitat.

Landslides/mudslides

This threat was scored as high impact for the Carolinian population but deemed not a threat for the Appalachian population. In addition to being a potential source of contamination, storm water discharges into the Niagara Gorge can cause slope instability and increase the risk of erosion and landslides (Yagi and Tervo 2008; Markle et al. 2013). Landslides and mudslides pose a serious threat to Allegheny Mountain Dusky Salamander habitat (Yagi 2008; Markle et al. 2013). Such events occur frequently in the Niagara gorge and have altered habitats near occupied sites(Yagi and Tervo 2008). They could occur more often if further development takes place on the escarpment due to increase in impervious surfaces, or if there is an increase in the frequency of heavy precipitation events as forecast by some climate models (Brooks 2009).

Recreational activities

This threat was scored as low impact for both populations of Allegheny Mountain Dusky Salamander. At Covey Hill, the recreational activity that poses the greatest threat is the use of all-terrain vehicles in the species’ habitats. Although all-terrain vehicle use in riparian areas is limited, it has already caused habitat alteration, and possibly destroyed shelters. Repeated ford crossings can alter habitat, reduce water quality, and increase the risk of surrounding habitat or groundwater contamination through fuel leaks (Environment Canada 2014).

In Ontario, the millions of people who visit the Niagara Gorge every year have a negative effect on habitat quality through actions such as throwing garbage into the gorge and trampling riparian vegetation (Yagi and Tervo 2008; Markle et al. 2013). However, the salamander habitat is relatively inaccessible, although some hikers venture off the maintained trail into the Stream 1 habitat (Markle et al. 2013). Stream 2 is fenced off by Ontario Power Generation and is inaccessible to the public (W. Weller pers. comm. 2015). Signs of human presence suggest that some people do access the habitat (A. Boutin pers. obs.)

Climate change and severe weather

Climate change projections for North America include a rise in the mean temperature and a change in precipitation patterns, with less frequent but more intense precipitation events and longer inter-event droughts (Brooks 2009). These changes are expected to result in higher evapotranspiration rates, with attendant drying of surface water sources and lowering of the water table (Brooks 2009). Although Northern Dusky Salamander adults are able to tolerate some exceptionally long drought periods (11 months), repeated prolonged droughts over multiple years would pose problems. Modelling suggests that the likelihood of survival for adults subjected to exceptional droughts in one year is 28% but drops to 8%, 2%, and 0.06% for every additional year of drought (Price et al. 2012). The probability of emigration doubled over the 11-month drought period (Price et al. 2012). This threat would be amplified in areas with altered habitat. In related species, droughts can have adverse effects on Northern Dusky Salamander larvae and cause reduced oviposition and loss of eggs of Ocoee Salamander (D. ocoee; Camp and Tilley 2005).

On the other hand, hydrologic simulations carried out by Larocque et al. (2013) suggest that climate change could have a favourable effect on Allegheny Mountain Dusky Salamander population at Covey Hill over the long term (horizon of 2050), owing to an increase in the number of days of hydrologic activity in seepage areas. However, the model simulations indicated a very high probability of extinction for seeps located at an elevation of 162 and 177 m, with almost zero abundance beyond 162 m. Abundance would nonetheless be increased at elevations of 144 and 150 m (Larocque et al. 2013). Based on the information currently available for Covey Hill, a large proportion (68.9%) of observations of Allegheny Mountain Dusky Salamander are from elevations above 162 m (n=212) with only 22.2% from elevations below 150 m (BORAQ 2015).

An increase in the frequency of torrential rainfall, such as the event that occurred in the Covey Hill area in 2011 with the passage of Tropical Storm Irene, could alter the species’ habitat (A. Boutin pers. obs.). In the Niagara Gorge, such rainfall events could have disastrous effects, causing landslides and the discharge of large quantities of poor quality water into the habitat. Torrential rainfall could also cause mortalities by carrying off salamanders or by washing away nests. In the Niagara Gorge, larvae and adults could easily be swept into the Niagara River, far from suitable habitats. In addition, breeding and overwintering habitats could be destroyed or rendered inaccessible.

Blaustein et al. (2010) provided a wide-ranging review of the direct and indirect effects of climate change on amphibian populations. Hydrogeological modelling of the Covey Hill aquifer, combined with ecological modelling based on Allegheny Mountain Dusky Salamander (Larocque et al. 2013), shows that future climate scenarios could favour the species owing to increased water flows (Larocque et al. 2013). However, the cumulative impacts are expected to be complex. Lowe (2012) observed a decline in the abundance of Spring Salamander adults and larvae associated with an increase in annual precipitation over a 12-year period. Climate models predict a reduction in the geographic distribution of all Appalachian salamander species as early as 2020 (Milanovitch et al. 2010). A reduction in the body size of plethodontids is also expected to occur in response to climate change. This phenomenon has been observed in six Plethodon species whose body size decreased 2% - 18% over a period of 55 years (Caruso et al. 2014). When standardized for within-population variation, this corresponds to a body size reduction of about 1% per generation. A size reduction of this magnitude in Allegheny Mountain Dusky Salamander may potentially reduce long-term recruitment.

Limiting factors

Because of its cutaneous respiration and its limited dispersal ability, Allegheny Mountain Dusky Salamander is restricted to specific habitats. The species’ specialized environmental needs, its life-history strategy (low reproductive rate), and its vulnerability to predation and competition are limiting factors that contribute to the isolation of the Canadian populations and the species’ vulnerability. Individuals mature relatively late (at 3 – 4 years), and although they reproduce annually, clutch size is generally small (11 – 14 eggs). As suggested for another plethodontid associated with streams and seeps, Coeur d’Alene Salamander (Plethodon idahoensis), this reproductive strategy may reduce the species’ capacity to recover from stochastic events (British Columbia Ministry of Environment 2015).

Given the small size of the Canadian populations and their isolation, the threats to Allegheny Mountain Dusky Salamander are particularly severe because they increase the risk of extirpation due to stochastic events. The species’ distribution in Québec and Ontario is so restricted that any degradation or loss of habitat is likely to compromise the long-term survival of the populations. Owing to their isolation, Canadian populations are at risk from any loss of genetic diversity, which could also compromise their persistence. Small populations are particularly vulnerable to the deleterious effects of inbreeding (Hedrick and Klinowski 2000).

Because headwater streams are small and slow flowing, they tend to be less permanent and therefore offer limited habitats for semi-aquatic salamanders (Petranka and Smith 2005). Furthermore, headwater streams are among the ecosystems that are most likely to become degraded (Power et al. 1988) because they are small and depend heavily on prevailing conditions in the watershed (Bank et al. 2006). These streams are greatly influenced by precipitation and, owing to their poor buffering capacity, they are vulnerable to contamination by atmospheric pollutants and to acidification (Fitzgerald et al. 1991; Petranka and Smith 2005; Bank et al. 2006; Green and Peloquin 2008).

Number of locations

Appalachian population

At Covey Hill, the 11 occurrences of Allegheny Mountain Dusky Salamander are linked and fed by groundwater from a single aquifer (Environment Canada 2014). A reduction in the level or quality of the water table from human activities or from climate change effects could potentially rapidly affect all occurrences of the species. The Covey Hill population is therefore considered a single location.

Carolinian population

In the Niagara Gorge, the two streams inhabited by the species can each be considered a location, which could be affected relatively rapidly by a single threatening event. They emanate from different water sources and are separated by at least 350 m of unsuitable habitat. A decrease in the supply of water, contamination of the water sources, or a landslide could cause the disappearance of salamanders at either site.

Protection, status and ranks

Legal protection and status

Under federal laws, Allegheny Mountain Dusky Salamander, Great Lakes / St. Lawrence population (now termed Appalachian population) was listed as Threatened on the List of Wildlife Species at Risk (Schedule 1) of the Species at Risk Act (SARA) in 2009. The Carolinian population was listed as Endangered on Schedule 1 of SARA in the same year. A recovery strategy was prepared for Allegheny Mountain Dusky Salamander, Great Lakes / St. Lawrence population (Environment Canada 2014), and the recovery measures implemented in Québec are described therein. A [proposed] recovery strategy was prepared for Allegheny Mountain Dusky Salamander, Carolinian population (Environment and Climate Change Canada 2016) and posted on the Species at Risk Public Registry in March of 2016. The critical habitat for the species in Québec has been identified and includes suitable habitat within 11 occurrences as well as the entire area of the peat bog on the top of Covey Hill (Appendix 7; Environment Canada 2014). An action plan for this population is currently under preparation (S. Giguère pers. comm. 2016) and due to be posted on the Species at Risk Public Registry by 2019 (Environment Canada 2014). The proposed critical habitat for the species in Ontario has been identified and is available for public review on the Species at Risk Public Registry. However, the document has not been finalized and information is subject to change.

The Québec government designated Allegheny Mountain Dusky Salamander as Threatened under the ,Act respecting threatened or vulnerable species, (CQLR, c. E-12.01) in 2009. That act gives the Ministère des Forêts, de la Faune et des Parcs (MFFP) responsibility for ensuring the protection of wildlife in Québec. The ,Act respecting the conservation and development of wildlife, (CQLR, c. C-61.1) prohibits purchasing, selling, and keeping of specimens in captivity. The MFFP has carried out legal mapping of Allegheny Mountain Dusky Salamander habitats, which involved regional consultations; however, it is unlikely that the legal implementation will be completed before 2018 (Y. Dubois pers. comm. 2015). Pursuant to section 22 of the ,Environment Quality Act, (CQLR, c. Q-2), a certificate of authorization is required prior to undertaking any construction or industrial activity that negatively affects a river, stream, lake, pond, marsh, or peat bog. Sometimes, work is undertaken without prior authorization from the government (S. Nadeau pers. comm. 2010). An update of the provincial recovery plan is under preparation in Québec, and actions to be implemented for the species’ recovery over a 10-year horizon have been identified (Équipe de rétablissement des salamandres de ruisseaux, in prep.).

In Ontario, the species has been designated as endangered by the Committee on the Status of Species at Risk in Ontario (COSSARO). It is included on the Species at Risk in Ontario List by the Ministry of Natural Resources and Forestry and is protected under Ontario’s, Endangered Species Act, 2007 (S.O. 2007, c. 6), which protects individuals and habitats of wildlife species. Ontario’s Fish and Wildlife Conservation Act, 2007 (S.O. 1997, c. 41) makes it illegal to hunt, trap, keep, sell, or purchase live specimens without a government permit. The specific habitat of Allegheny Mountain Dusky Salamander in Stream 1 has been described and mapped in detail (Yagi and Tervo 2008). This mapping will be used to develop a specific habitat regulation as provided for in the application of Ontario’s Endangered Species Act, 2007. The Stream 2 locality has not yet been mapped (Markle et al. 2013). A provincial recovery plan has been published in Ontario and sets out the recovery actions that have been completed and those that will be carried out in the future (Markle et al. 2013).

Non-legal status and ranks

NatureServe (2015) has assigned the Allegheny Mountain Dusky Salamander a global conservation status rank of G5 (secure) because of its widespread distribution in North America and the presence of many stable populations. The species is ranked as nationally secure (N5) in the United States, but nationally imperilled (N2) in Canada. It is considered critically imperilled (S1) in Québec and Ontario. It is listed as Least Concern on the International Union for the Conservation of Nature (IUCN) Red List (IUCN 2016).

Habitat protection and ownership

At present, only 2% of the area of occupancy of Allegheny Mountain Dusky Salamander is located on protected land (CNC 2015; A. Filion pers. comm. 2015). At Covey Hill, the entire area of occupancy of Allegheny Mountain Dusky Salamander is located on private land belonging to about 100 landowners (COSEWIC 2007). The Nature Conservancy of Canada bought 1.24 km² of land as part of its Covey Hill Natural Laboratory initiative, protecting a portion of the Covey Hill bog (Larocque et al. 2006). Protection of the bog, which is sensitive to external disturbances, does not guarantee the ecological and hydrological integrity of the habitat (Pellerin and Lavoie 2003). The NCC also provides permanent protection for an additional 2.97 km² of habitat through conservation easements (servitudes) signed with private landowners (C. Deland pers. comm. 2015; Table 3; Appendix 8). South of the border, in New York State, a similar area (2.16 km²), called “The Gulf Unique Area,” is protected (Larocque et al. 2006).

Protection measures for stream salamanders relating to silvicultural practices were adopted and have been applied since 2006 on provincial public lands that are subject to forest management (MRNF 2008; L. Deschênes pers. comm. 2015). However, in Québec, the range of Allegheny Mountain Dusky Salamander is located completely on privately owned land (Environment Canada 2014; C. Deland pers. comm. 2015), which is not covered by habitat protection measures. The private landowners are nonetheless encouraged to apply the protection measures on a voluntary basis at Covey Hill.

The intermittent streams used by the species are not visible on 1:20,000-scale maps or on aerial photographs. They can therefore be overlooked during environmental assessments, especially if the streams have dried up (Snodgrass et al. 2007; Peterman et al. 2008).

In Ontario, the species’ habitat benefits from some protection because it is owned and managed by the Niagara Parks Commission. While this will prevent development, it does not guarantee the continued quantity and quality of the groundwater supply to the streams and seeps in which the species dwells (Markle et al. 2013).

Acknowledgements and authorities contacted

The report writer wishes to thank the Centre de données sur le patrimoine naturel du Québec; the Ministère des Forêts, de la Faune et des Parcs du Québec (MFFP); the Ontario Natural Heritage Information Centre; and the Ontario Ministry of Natural Resources and Forestry, which provided data on the species’ distribution in Canada. The report writer also thanks Alain Filion for providing estimates of the extent of occurrence and the area of occupancy. The Nature Conservancy of Canada for providing information and mapping of protected areas. Special thanks go to Wayne Weller, Claudine Laurendeau, Carine Deland, Anne Yagi, Nathalie Tessier, Yohann Dubois, Lise Deschênes and Sylvain Giguère for their advice and expertise, and to Réjean Boutin for reviewing the French version. The comments from Jim Bogart, Joe Crowley, Ruben Boles, Sylvain Giguère, David M. Green, Isabelle Gauthier, Dennis Murray, Barbara Chunn, Marie Archambault, Chris Rohe, Scott Reid and COSEWIC Amphibians and Reptiles Subcommittee members on earlier drafts of the report are greatly appreciated. The report writer also extends thanks to the authors of the previous reports on this species: Tricia Markle, Joël Bonin and Robert Alvo.

Authorities contacted

Bogart, Jim – Former Co-chair of the COSEWIC Amphibians and Reptiles Specialist Subcommittee.

Bouthillier, Lyne – Species at risk research officer, Ministère des Forêts, de la Faune et des Parcs, Secteur des opérations régionales, Direction de la gestion de la faune, Longueuil, Québec.

Cook, Francis, R. – Emeritus Curator and Research Associate, Canadian Museum of Nature, Ottawa, Ontario.

Crowley, Joe – Herpetology Species at Risk Specialist, Species Conservation Policy Branch, Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario.

Deland, Carine – Project Officer, Nature Conservancy of Canada, Montréal, Québec.

Deschênes, Lise – Ministère des Forêts, de la Faune et des Parcs, Secteur des forêts, Direction de l’aménagement et de l’environnement forestiers, Québec City, Québec.

Dubois, Yohann – Amphibian and reptile issue coordinator, Ministère des Forêts, de la Faune et des Parcs, Secteur de la faune et parcs, Direction de l’expertise sur la faune terrestre, l’herpétofaune et l’avifaune, Québec, Québec.

Filion, Alain – Scientific and GIS Project Officer, COSEWIC and CITES Science Support, Canadian Wildlife Service, Environment Canada, Gatineau, Québec.

Furrer, Martina – Biodiversity Information Biologist, Ontario Natural Heritage Information Centre, Ontario Ministry of Natural Resources and Forestry, Peterborough, Ontario.

Gauthier, Isabelle – Provincial coordinator of threatened and vulnerable wildlife species, Ministère des Forêts, de la Faune et des Parcs, Secteur de la faune et des parcs, Direction générale de la gestion et des habitats, Québec, Québec.

Giguère, Sylvain – Species at Risk Recovery Biologist, Environment Canada, Québec Region, Canadian Wildlife Service, Québec City, Québec.

Green, David M. – Professor, Director of the Redpath Museum, McGill University, Montréal, Québec.

Jones, Neil – Scientific Project Officer and ATK Coordinator, COSEWIC Secretariat, Canadian Wildlife Service, Environment Canada, Gatineau, Québec.

Laurendeau, Claudine – Wildlife technician, Ministère des Forêts, de la Faune et des Parcs, Secteur de la faune et des parcs, Direction de l’expertise sur la faune terrestre, l’herpétofaune et lavifaune, Québec, Québec.

McBride, Bev – Project Officer, COSEWIC Secretariat, Canadian Wildlife Service, Environment Canada, Gatineau, Québec.

Reid, Scott – Research Scientist, Endangered Species, Aquatic Research and Monitoring Section, Ontario Ministry of Natural Resources and Forestry, Trent University, Peterborough, Ontario.

Rouleau, Sébastien – Coordinator, Research and Conservation, Ecomuseum Zoo, St. Lawrence Valley Natural History Society, Sainte-Anne-de-Bellevue, Québec.

Seutin, Gilles – Coordinator, Species at Risk Program, Parks Canada, Gatineau, Québec.

Schnobb, Sonia – Administrative Assistant, COSEWIC Secretariat, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario.

Tessier, Nathalie – Biologist, Ministère des Forêts, de la Faune et des Parcs, Secteur des opérations régionales, Direction de la gestion de la faune, Longueuil, Québec.

Weller, Wayne – Member of the Ontario Dusky Salamander Recovery and Implementation Team, Niagara-on-the-Lake, Ontario.

Yagi, Anne – Management Biologist, Ontario Ministry of Natural Resources and Forestry, Guelph District, Vineland Station, Ontario.

Information sources

Alvo, R., and J. Bonin. 2003. Rapport sur la situation de la salamandre sombre des montagnes (Desmognathus ochrophaeus) au Québec. Société de la faune et des parcs du Québec. vi + 32 p.

Anderson, J.A., and S.G. Tilley. 2003. Systematics of the Desmognathus ochrophaeus complex in the Cumberland Plateau of Tennessee. Herpetological Monographs 17:75-100.

Arnold, S.J., N.L. Reagan, and P.A. Verrell. 1993. Reproductive isolation and speciation in plethodontid salamanders. Herpetologica 49:216-288.

Ash, A.N. 1997. Disappearance and return of salamanders from clearcut plots in the southern Blue Ridge Mountains. Conservation Biology 11:983-989.

Ashton, R.E., Jr. 1975. A study of movements, home range and winter behavior of Desmognathus fuscus (Rafinesque). Journal of Herpetology 9(1):85-91.

Ashton, R.E., Jr. 1976. Endangered and threatened amphibians and reptiles in the United States. Society for the Study of Amphibians and Reptiles, Herpetological Circular 5. 65 p.

Ashton, R.E., Jr., and P.S. Ashton. 1978. Movements and winter behavior of Eurycea bislineata (Amphibia, Urodela, Plethodontidae). Journal of Herpetology 12:295-298.

Baker, M.R. 1987. Synopsis of the nematoda parasitic in amphibians and reptiles. Occasional Papers in Biology. Memorial University of Newfoundland, St. John’s Newfoundland, Canada. 325 p.

Bank, M.S., J.B. Crocker, S. Davis, D.K. Brotherton, R. Cook, J. Behler, and B. Connery. 2006. Population decline of Northern Dusky Salamanders at Acadia National Park, Maine, USA. Biological Conservation 130:230-238.

Bank, M.S., J.R. Burgess, D.C. Evers, and C.S. Loftin. 2007. Mercury contamination of biota from Acadia National Park, Maine: a review. Environmental Monitoring and assessment 126:105-115.

Barr, G.E., and K.J. Babbitt. 2002. Effects of biotic and abiotic factors on the distribution and abundance of larval two-lined salamanders (Eurycea bislineata) across spatial scales. Oecologia 133:176-185.

Barr, G.E., and K.J. Babbitt. 2007. Trout affect the density, activity and feeding of a larval plethodontid salamander. Freshwater Biology 52:1239-1248.

Barrett, K., B.S. Helms, C. Guyer, and J.E. Schoonover. 2010. Linking process to pattern: causes of stream-breeding amphibian decline in urbanized watersheds. Biological Conservation 143(9):1998-2005.

Barrington, S., H. Philion, and J. Bonin. 1993. An evaluation of the water reserve potentials: the ecological region of the Covey Hill “Gulf.” Report for the Nature Conservancy of Canada. 44 p. + appendices. Sainte-Anne-de-Bellevue, Québec.

Barton, C. 2011. Coal Mining Versus Water Quality: An Electrifying Topic. American Water Resources Association: Water Resource Impact 13:23-24.

Bd-Maps, The Global Mapping Project. 2015. Surveillance – Canada. Imperial College London. Web site: [accessed September 2015].

Beachy, K.B. 1995. Effects of larval growth history on metamorphosis in a stream-dwelling salamander (Desmognathus ochrophaeus). Journal of Herpetology 29 (3):375-382.

Beamer, D.A., and T. Lamb. 2008. Dusky salamanders (Desmognathus, Plethodontidae) from the Coastal Plain: Multiple independent lineages and their bearing on the molecular phylogeny of the genus. Molecular Phylogenetics and Evolution 47(1):143-153.

Bernardo, J. 1994. Experimental analysis of allocation in two divergent, natural salamander populations. American Naturalist 143(1):14-38.

Bernhardt, E.S., and M.A. Palmer. 2011. The environmental costs of mountaintop mining valley fill operations for aquatic ecosystems of the Central Appalachians. Year in Ecology and Conservation Biology. Annals of New York Academy of Science 1223:39-57.

Bider, J.R., and S. Matte. 1991. Atlas des amphibiens et des reptiles du Québec. Société d'histoire naturelle de la vallée du Saint-Laurent et ministère du Loisir, de la Chasse et de la Pêche, Québec. 429 p.

Bider, J.R., and S. Matte. 1994. Atlas des amphibiens et des reptiles du Québec. Société d’histoire naturelle de la vallée du Saint-Laurent, Saint-Anne-de-Bellevue, Québec and Ministère de l’Environnement et de la Faune, Direction de la faune et des habitats, Québec. 106 p.

Bider, J.R., and S. Matte. 1996. The Atlas of Amphibians and Reptiles of Québec. St. Lawrence Valley Natural History Society and the Ministère de l’Environnement et de la Faune, Direction de la faune et des habitats: Québec. 106 p.

Bishop, S.C., and H.P. Chrisp. 1933. The nest and young of the Allegheny salamander Desmognathus fuscus ochrophaeus (Cope). Copeia 1933:194-198.

Bishop, S.C. 1941. The salamanders of New York. New York State Museum Bulletin 324: 1-365.

Bishop, S.C. 1943. Handbook of Salamanders. Comstock Publishing Company Inc., Ithaca, New York. 555 pp.

Blaustein, A.R., J.M. Romansic, J.M. Kiesecker, and A.C. Hatch. 2003. Ultraviolet radiation, toxic chemicals and amphibian population declines. Diversity and Distributions 9(2):123-140.

Blaustein, A.R., S.C. Walls, B.A. Bancroft, J.J. Lawler, C.L. Searle, and S.S. Gervasi. 2010. Direct and indirect effects of climate change on amphibian populations. Diversity 2(2):281-313.

Bleakney, J.S. 1958. A zoogeographical study of the amphibians and reptiles of eastern Canada. National Museum of Canada Bulletin 155:1-119.

Bonin, J. 1989. Statut des espèces de salamandres de ruisseaux dans le comté de Huntingdon, Québec. Rapport final présenté à la Direction générale de la ressource faunique, Ministère du Loisir, de la Chasse et de la Pêche, Québec. 39 p.

Bonin, J. 1993. Protection des salamandres du piémont des Adirondacks. Report for the Nature Conservancy of Canada. April 1993. 12 p.

Bonin, J. 1994. Climatic and landscape changes versus population decline and conservation: the Chorus Frog and the Mountain Dusky Salamander in Québec, in W.B. Preston (ed.). Proceedings from the Fourth Annual Meeting of the Task Force on Declining Amphibian Populations in Canada (DAPCAN IV), Winnipeg, Manitoba, p. 70-74.

Bonin, J. 1999. COSEWIC status report on the spring salamander Gyrinophilus porphyriticus in Canada in COSEWIC assessment and status report on the spring salamander Gyrinophilus porphyriticus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 16 pp.

Bonin. J. 2000. Stratégie de rétablissement des salamandres de ruisseaux du complexe appalachien: Gyrinophilus porphyriticus, Desmognathus ochrophaeus et Desmognathus fuscus. (initial document – evaluation of the situation). Conservation de la nature – bureau du Québec. 13 p.

Bonett, R.M., and P.T. Chippindale. 2004. Speciation, phylogeography and evolution of life history and morphology in plethodontid salamanders of the Eurycea multiplicata complex. Molecular Ecology 13:1189-1203.

BORAQ, 2015. Banque des observations des Reptiles et Amphibiens du Québec. Ministère des Forêts, de la Faune et des Parcs.

Bouthillier, L. 2011. Inventaire d’acquisition de connaissance sur la salamandre sombre des montagnes à Covey Hill. Rapport de terrain 2010. Ministère des Resources naturelles et de la Faune, Longueuil, Québec.

Bouthillier, L. 2016. Pers. comm. Email exchange with A. Boutin. August 2016. Research officer, Ministère des Forêts, de la Faune et des Parcs, Direction de la gestion de la faune de l’Estrie, de Montréal, de la Montérégie et de Laval, Longueuil, Québec.

Boutin, A. 2003. Rapport préliminaire à l’élaboration d’un projet de maîtrise sur la caractérisation de l’habitat et la génétique des populations de la salamandre sombre des montagnes (Desmognathus ochrophaeus) et des espèces apparentées du genre Desmognathus. Report for the Équipe de rétablissement des salamandres de ruisseaux. September 2003. 9 pp.

Boutin, A. 2004. Rapport sur l’inventaire des salamandres sombres des montagnes (Desmognathus ochrophaeus) et sombres du nord (Desmognathus fuscus) réalisé dans la région de Covey Hill (Québec), de mai à septembre 2004. Submitted to the Équipe de rétablissement des salamandres de ruisseaux du Québec. 11 p.

Boutin, A. 2006. Caractérisation de l’habitat d’une communauté de salamandres de ruisseaux comportant des hybrides. Mémoire présenté à la Faculté des études supérieures en vue de l’obtention du grade de Maître ès sciences (M.Sc.) en sciences biologiques, Département de sciences biologiques, Université de Montréal, April 2006. 91 p.

Bowles, D.E., and T.L. Arsuffi. 1993. Karst aquatic ecosystems of the Edwards Plateau region of central Texas, USA: A consideration of their importance, threats to their existence, and efforts for their conservation. Aquatic Conservation: Marine and Freshwater Ecosystems 3(4):317-329.

Brannon, M.P., and B.A. Purvis. 2008. Effects of sedimentation on the diversity of salamanders in a southern Appalachian headwater stream. Journal of North Carolina Academy of Science 124:18-22.

Brimley, C.S. 1907. Keys to North Carolina snakes, lizards and batrachians. Journal of the Elisha Mitchell Scientific Society 23:141-160.

B.C. Ministry of Environment. 2015. Management Plan for the Coeur d’Alene Salamander (Plethodon idahoensis) in British Columbia, B.C. Ministry of Environment, Victoria, British Columbia, 24 p.

Brodie, E.D. 1977. Salamander antipredator postures. Copeia 3:523-535.

Brodie, E.D. Jr, and R.R. Howard. 1973. Experimental study of Batesian mimicry in the salamanders Plethodon jordani and Desmognathus ochrophaeus. American Midland Naturalist 90(1) 38-46.

Brodie, E.D., Jr., R.T. Novak, and W.R. Harvey. 1979. The effectiveness of antipredator secretions and behaviour of selected salamanders against shrews. Copeia 1979:270-274.

Brooks, R.T. 2009. Potential impacts of global climate change on the hydrology and ecology of ephemeral freshwater systems of the forests of the northeastern United States. Climate Change 95:469-483.

Bruce, R.C. 1972. Variation in the life cycle of the salamander Gyrinophilus porphyriticus. Herpetologica 28:230-245.

Bruce, R.C. 1979. Evolution of paedogenesis in salamanders of the genus Gyrinophilus. Evolution 33:998-1000.

Bruce, R.C. 1986. Upstream and downstream movements of Eurycea bislineata and other salamanders in a Southern Appalachian stream. Herpetologica 42: 149-155.

Bruce, R.R. 1993. Sexual size dimorphism in desmognathine salamanders. Copeia 1993(2):313-318.

Burton, T.M. and G.E. Likens. 1975a. Energy flow and nutrient cycling in salamander populations in the Hubbard Brook Experimental Forest, New Hampshire. Ecology 56:1068-1080.

Burton, T.M., and G.E. Likens. 1975b. Salamander populations and biomass in the Hubbard Brook Experimental Forest, New Hampshire. Copeia 1975:541-546.

Camp, C.D., and S.G. Tilley. 2005. Desmognathus ocoee, Ocoee Salamander, in M. Lannoo (ed.). Amphibian Declines: The Conservation Status of United States Species, University of California Press, USA. p. 719-721

Caruso, N.M., M.W. Sears, D.C. Adams, and K.R. Lips. 2014. Widespread rapid reductions in body size of adult salamanders in response to climate change. Global Change Biology 20(6):1751-1759.

CDPNQ. 2015. Centre de données sur le patrimoine naturel du Québec. Website: [accessed October 2015].

Cecala, K.K. 2012. The Role of Behavior in Influencing Headwater Salamander Responses to Anthropogenic Development. PhD Thesis, University of Georgia, Athens, GA. Vii+146 p.

Cecala, K.K., S.J. Price, and M.E. Dorcas. 2009. Evaluating existing movement hypotheses in linear systems using larval stream salamanders. Canadian Journal of Zoology 87:292-298.

Cecala, K.K., W.H. Lowe, and J.C. Maerz. 2014. Riparian disturbance restricts in-stream movement of salamanders. Freshwater Biology 59(11):2354-2364.

Centre d’expertise hydrique du Québec. 2015. Répertoire des barrages. Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques. Website:[accessed October 2015].

Conservation de la Nature Canada (CNC). 2013. Inventaire et désignation de l'habitat légal de la salamandre sombre des montagnes. Mise à jour du rapport technique produit en mars 2012. March 2013. 2p.

Conservation de la nature Canada (CNC). 2015. Rapport d'Activité 30A-PIH6548, Inventaire de la salamandre sombre des montagnes. Rapport d'inventaire de 2014. 2 p.

Conant, R., F.R. Cagle, C.J. Goin, C.H., Jr. Lowe, W.T. Neill, M. Graham Netting, K.P. Schmidt, C.E. Shaw, R.C. Stebbins, and C.M. Bogert. 1956. Common names for North American amphibians and reptiles. Copeia 3:172-185.

Conant, R. 1975. A field guide to reptiles and amphibians of eastern and central North America. Second edition. Houghton Mifflin Co., Boston, Massachusetts. 429 p.

Conant, R., and J. T. Collins. 1998. A field guide to reptiles and amphibians: eastern and central North America. Third edition. Houghton Mifflin Co., Boston, Massachusetts. 450 p.

Cook, F.R., and J.S. Bleakney. 1960. Additional records of stream salamanders in New Brunswick. Copeia 1960:362-363.

Cope, E.D. 1859. On the primary divisions of the Salamandridae, with descriptions of two new species. Proceedings of the Academy of Natural Sciences of Philadelphia 11:122-128.

Corn, P.S., and R.B. Bury. 1989. Logging in western Oregon: responses of headwater habitats and stream amphibians. Forest Ecology and Management 29:39-57.

COSEWIC. 2007. COSEWIC assessment and update status report on the Allegheny Mountain Dusky Salamander Desmognathus ochrophaeus (Great Lakes/St. Lawrence population and Carolinian population) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. Viii + 32 p.

COSEWIC. 2012. COSEWIC assessment and status report on the Northern Dusky Salamander Desmognathus fuscus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xiii + 56 p. (www.registrelep-sararegistry.gc.ca/default_e.cfm).

COSEWIC. 2015a. Guidelines for Recognizing Designatable Units. Approved by COSEWIC in November 2014. Committee on the Status of Endangered Wildlife in Canada. Website: [accessed July 2015].

COSEWIC. 2015b. Instructions for the Preparation of COSEWIC Status Reports. Approved by COSEWIC in November 2013, updated in August 2014. Committee on the Status of Endangered Wildlife in Canada. Website: [accessed July 2015].

Côté, M.-J., Y. Lachance, C. Lamontagne, M. Nastev, R. Plamondon, and N. Roy. 2006. Atlas du bassin versant de la rivière Châteauguay. Ministère du Développement durable, de l’Environnement et des Parcs, en collaboration étroite avec la Commission géologique du Canada et l’Institut national de la recherche scientifique – Eau, Terre et Environnement, Québec. 64 p.

Cupp, P.V., Jr. 1994. Salamanders avoid chemical cues from predators. Animal Behaviour 48:232-235.

Danstedt, R.T., Jr. 1975. Local geographic variation in demographic parameters and body size of Desmognathus fuscus (Amphibia: Plethodontidae). Ecology 56:1054-1067.

Davic, R.D., and H.H. Welsh. 2004. On the ecological roles of salamanders. Annual Review of Ecology, Evolution, and Systematics 35:405-434.

Deland, C., pers. comm. 2015. Email exchange with A. Boutin. September 2015. Chargée de projet, Conservation de la nature Canada, Montréal, Québec.

Deland, C., and A. Sierra. 2016. Rapport final – Développement d’un outil d’intendance pour l’habitat de la salamandre sombre des montagnes à Covey Hill. Conservaton de la nature Canada, Montréal, Québec, 20 p.

DeMaynadier, P.G., and M.L. Hunter. 1998. Effects of silvicultural edges on the distribution and abundance of amphibians in Maine. Conservation Biology 12(2):340-352.

Denman, N.S. 1963. A range extension of the Dusky Salamander in Québec. Canadian Field-Naturalist 77:62.

Denman, N.S., F.W. Schueler, and W.F. Weller. 1990. Geographic Distribution: Eurycea bislineata bislineata. Herpetological Review 21(2):36.

Deschênes, L., pers. comm. 2015. Email exchange with A. Boutin. September 2015. Ministère des Forêts, de la Faune et des Parcs, Secteur des Forêts, Direction de l'aménagement et de l'environnement forestiers, Québec City, Québec.

Desroches, J.-F., and I. Picard. 2001. Inventaire faunique de la vallée du ruisseau Gulf et de la rivière au Saumon en Estrie. Rapport réalisé pour le Comité du marais de Kingsbury.

Desroches, J.F., and D. Rodrigue. 2004. Amphibiens et reptiles du Québec et des maritimes. Éditions Michel Quintin, Waterloo, Québec. 288 p.

Desroches, J.-F. and D. Pouliot. 2005. Premières mentions et répartition de la salamandre sombre du Nord, Desmognathus fuscus, sur la rive nord du fleuve Saint-Laurent, au Québec. Canadian Field-Naturalist 119(1):105-109.

Dodd, C.K., Jr. 1990. The influence of temperature and body size on duration of immobility in salamanders of the genus Desmognathus. Amphibia-Reptilia 11: 401-410.

Dodd, C.K., Jr. J.A. Johnson, and E.D. Brodie, Jr. 1974. Noxious skin secretions of an eastern small Plethodon, P. nettingi hubrichti. Journal of Herpetology 8 (1):89-92.

Dubois, Y., pers. comm. 2015. Email exchange with A. Boutin. September 2015. Coordinator of amphibian and reptile files, Ministère des Forêts, de la Faune et des Parcs, Secteur de la faune et des parcs, Service de la conservation de la biodiversité et des milieux humides, Direction de l’expertise sur la faune terrestre, l’herpétofaune et l’avifaune, Québec City, Québec.

Dunn, E.R. 1917. The salamanders of the genera Desmognathus and Leurognathus. Proceedings of the United States Natural Museum 53:393-433.

Dunn, E.R. 1926. The salamanders of the family Plethodontidae. Smith College 50th Anniversary Publication, Northhampton, Massachusetts. 441 p.

Dunne, T., and L.B. Leopold. 1978. Water in Environmental Planning. First Edition. W.H. Freeman and Company, New York. 818 p.

Elliott, J.M. 2002. The drift distances and time spent in the drift by freshwater shrimps, Gammarus pulex, in a small stony stream, and their implications for the interpretation of downstream dispersal. Freshwater Biology 47:1403-1418.

Environment and Climate Change Canada. 2016. Recovery Strategy for the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) – Carolinian population in Canada [Proposed] (PDF). Species at Risk Act Recovery Strategy Series. Environment and Climate Change Canada, Ottawa. 23 pp. + Appendices.

Environment Canada. 2014. Recovery Strategy for the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus), Great Lakes/St. Lawrence Population, in Canada (PDF). Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. iv + 25 pp.()

Evans, A.L., and D.C. Forester. 1996. Conspecific recognition by Desmognathus ochrophaeus using substrate-borne odor cues. Journal of Herpetology 30:447-451.

Fagan, W.F., E.H.C. Grant, H.J. Lynch, and P.J. Unmack. 2009. Riverine landscapes: Ecology for an alternative geometry, in S. Cantrell, C. Cosner and S. Ruan (eds.). Spatial Ecology, Chapman and Hall / CRC Press, Boca Raton, Florida. 360 p.

Feder, M.E. 1976. Lunglessness, body size, and metabolic rate in salamanders. Physiological Zoology. 49:398-406.

Feder, M.E. 1983. Integrating the ecology and physiology of plethodontid salamanders. Herpetologica 39:291-310.

Feder, M.E., and W.W. Burggren. 1985. Cutaneous gas exchange in vertebrates: Design, pattern, control, and implications. Biological Review 60:1-45.

Feder, M.E., and P.L. Londos. 1984. Hydric constraint upon foraging in a terrestrial salamander, Desmognathus ochrophaeus (Amphibia: Plethodontidae). Oecologia 64:413-418.

Filion, A. pers. comm. 2015. Email exchange with A. Boutin. August 2015. Scientific and GIS Project Officer, Species Assessment, COSEWIC Secretariat, Population Conservation and Management Division, Canadian Wildlife Service, Ottawa, Ontario.

Fitzgerald, W.F., G.M. Vandal, and R.P. Mason. 1991. Atmospheric cycling and air-water exchange of mercury over mid-continental lacustrine regions. Water, Air and Soil Pollution 56:745-767.

Fitzpatrick, L.C. 1973. Energy allocation in the Allegheny Mountain salamander, Desmognathus ochrophaeus. Ecological Monographs 43: 43-58.

Ford, W.M., B.R. Chapman, M.A. Menzel, and R.H. Odom. 2002. Stand age and habitat influences on salamanders in Appalachian cove hardwood forests. Forest Ecology and Management 155(1):131-141.

Forester, D.C. 1977. Comments on the female reproductive cycle and philopatry in Desmognathus ochrophaeus (Amphibia, Urodela, Plethodontidae). Journal of Herpetology 11:311-316.

Forester, D.C. 1979. The adaptiveness of parental care in Desmognathus ochrophaeus (Urodela: Plethodontidae). Copeia 1979:332-341.

Forester, D.C. 1981. Parental care in the salamander Desmognathus ochrophaeus: female activity pattern and trophic behavior. Journal of Herpetology 15:29-34.

Forester, D.C. 1984. Brooding behavior by the mountain dusky salamander (Desmognathus ochrophaeus): Can the female presence reduce clutch desiccation? Herpetologica 40:105-109.

Formanowicz, D.R., Jr., and E.D. Brodie, Jr. 1993. Size-mediated predation pressure in a salamander community. Herpetologica 49(2):265-270.

Fortin, C., M. Ouellet, and P. Galois. 2004. Les amphibiens et les reptiles des îles de l'estuaire du Saint-Laurent: mieux connaître pour mieux conserver. Le Naturaliste Canadien 128(1):61-67.

Frenette, M. 2007. Bilan des actions de l’Équipe de rétablissement des salamandres de ruisseaux du Québec. Rapport rédigé pour l’Équipe de rétablissement des salamandres de ruisseaux. Ministère des Ressources naturelles et de la Faune. 59 p.

Frenette, M. 2008. Plan de conservation des salamandres de ruisseaux au mont Covey Hill, Montérégie, Conservation de la nature Canada et Équipe de rétablissement des salamandres de ruisseaux, Montréal. 57 p.

Frizzle, C. 2001. Inventaire biologique de 70 milieux humides de l’Estrie (région 05). Regroupement des associations pour la protection de l'environnement des lacs et cours d'eau de l'Estrie et du haut-bassin de la Saint-François. 42 p.

Frost, D.R. 2015. Amphibian Species of the World: an Online Reference. Version 6.0. Electronic Database accessible at. American Museum of Natural History, New York, USA. [accessed December 2, 2015].

Galois, P., and M. Ouellet. 2005. Le grand bois de Saint-Grégoire, un refuge pour l’herpétofaune dans la plaine montérégienne. Le naturaliste Canadien 129:37-43.

Gendron, A.D., C.A. Bishop, R. Fortin, and A. Hontela. 1997. In vivo testing of the functional integrity of the corticosterone-producing axis in mudpuppy (Amphibia) exposed to chlorinated hydrocarbons in the wild. Environmental Toxicology and Chemistry 16:1694-1706.

Gibbs, J.P. 1998. Distribution of woodland amphibians along a forest fragmentation gradient. Landscape Ecology 13:263-268.

Giguère, S., pers. comm. 2016. Email exchange with A. Boutin. August 2016. Species at Risk Recovery Biologist, Environment Canada, Québec Region, Canadian Wildlife Service, Québec City, Québec.

Goater, T.M., G.W. Esch, and A.O. Bush. 1987. Helminth parasites of sympatric salamanders: ecological concepts at infracommunity, component and compound community levels. American Midland Naturalist 118(2):289-300.

Gordon, D.M. 1979. New localities for the Northern Spring Salamander and the Four-toed Salamander in southwestern Québec. Canadian Field-Naturalist 93:193-195.

Grant, E.H.C, L.E. Green, and W.H. Lowe. 2009. Salamander occupancy in headwater stream networks. Freshwater Biology 54:1370-1378.

Grant, E.H.C., J.D. Nichols, W.H. Lowe, and W.F. Fagan. 2010. Use of multiple dispersal pathways facilitates amphibian persistence in stream networks. Proceedings of the National Academy of Sciences, USA 107:6936-6940.

Gray, J.E. 1850. Catalog of the Species of Amphibians in the collection of the British Museum, Part 2, Batrachia Gradientia. p. 31.

Green, D.M. (ed.). 2012. Noms français standardisés des amphibiens et des reptiles d’Amérique du Nord au nord du Mexique. Society for the Study of Amphibians and Reptiles. Herpetological Circular 40. 63 p.

Green, N.B., and T.K. Pauley. 1987. Amphibians and reptiles in West Virginia. University of Pittsburg Press, Pittsburg, Pennsylvania. xi + 241 p.

Green, L., and J.E. Peloquin. 2008. Acute toxicity of acidity in larvae and adults of four stream salamander species (Plethodontidae). Environmental Toxicology and Chemistry 3:2361-2367

Groupe Phragmites. 2012. Le roseau envahisseur: la dynamique, l’impact et le contrôle d’une invasion d’envergure. Le Naturaliste canadien 136(3):33-39.

Grover, M.C. 1998. Salamander Community Ecology. Unpubl. Ph.D. diss., University of Virginia, Charlottesville.

Grover, M.C. 2000. Determinants of salamander distribution along moisture gradients. Copeia 2000:156-168.

Grover, M.C., and H.M. Wilbur. 2002. Ecology of ecotones: Interactions between salamanders on a complex environmental gradient. Ecology 83:2112-2123.

Hairston, N.G. 1949. The local distribution and ecology of the Plethodontid salamanders of the southern Appalachian. Ecological Monographs 19:47-73.

Hairston, N.G. 1986. Species packing in Desmognathus salamanders: Experimental demonstration of predation and competition. American Naturalist 127:266-291.

Hairston, N.G. 1987. Community ecology and salamander guilds. Challenges to community theory. Cambridge University Press, New York, New York, USA. 230 p.

Hall, R.J. 1977. A population analysis of two species of streamside salamanders, Genus Desmognathus. Herpetologica 33:1109-1034.

Hawkins, C.P., M.L. Murphy, N.H. Anderson, and M.A. Wilzbach. 1983. Density of fish and salamanders in relation to riparian canopy and physical habitat in streams of the northwestern United States. Canadian Journal of Fisheries and Aquatic Sciences 40:1173-1185.

Hedrick, P.W., and S.T. Kalinowski. 2000. Inbreeding depression in conservation biology. Annual Review of Ecology and Systematics 31:139-162.

Herring, K., and P. Verrell. 1996. Sexual incompatibility and geographical variation in mate recognition systems: Tests in the salamander Desmognathus ochrophaeus. Animal Behaviour 52(2):279-287.

Hileman, K.S., and E.D. Brodie, Jr. 1994. Survival strategies of the salamander Desmognathus ochrophaeus: Interactions of predator-avoidance and anti-predator mechanisms. Animal Behaviour 47:1-6.

Holomuzki, J.R. 1980. Synchronous foraging and dietary overlap of three species of Plethodontid salamanders. Herpetologica 36:109-115.

Holomuzki, J.R. 1982. Homing behavior of Desmognathus ochrophaeus along a stream. Journal of Herpetology 16:307-309.

Hom, C.L. 1987. Reproductive ecology of female dusky salamanders, Desmognathus fuscus (Plethodontidae), in the southern Appalachians. Copeia 1987:768-777.

Houck, M.A., and E.D. Bellis. 1972. Comparative tolerance to desiccation in the salamanders Desmognathus f. fuscus and Desmognathus o. ochrophaeus. Journal of Herpetology. 6(3-4):209-215.

Houck, L.D., and K. Schwenk. 1984. The potential for long-term sperm competition in a plethodontid salamander. Herpetologica 40:410-415.

Houck, L.D., S.J. Arnold, and R.A. Thisted. 1985. A statistical study of mate choice: Sexual selection in a Plethodontid salamander (Desmognathus ochrophaeus). Evolution 39(2):370-386.

Houck, L.D., S.J. Arnold and A. Hickman. 1988. Test for sexual isolation in plethodontid salamanders (genus Desmognathus). Journal of Herpetology 22:186-191.

Howard, J.H., R.L. Wallace, and J.H. Larsen, Jr. 1983. Genetic variation and population divergence in the Larch Mountain Salamander (Plethodon larselli). Herpetologica 39:41-47.

Huheey, J.E., and R.A. Brandon. 1973. Rock-face populations of the mountain salamander, Desmognathus ochrophaeus, in North Carolina. Ecological Monographs 43:59-77.

IUCN. 2016. SSC Amphibian Specialist Group. 2015. Desmognathus ochrophaeus. The IUCN Red List of Threatened Species 2015: Web site: [accessed November 2016].

Jaeger, R.G. 1970. Potential extinction through competition between two species of terrestrial salamanders. Evolution 24(3):632-642.

Jaeger, R.G. 1971. Moisture as a factor influencing the distributions of two species of terrestrial salamanders. Oecologia 6:191-207.

Jaeger, R.G., J.A. Wicknick, M.R. Griffis, and C.D. Anthony. 1995. Socioecology of a terrestrial salamander: Juveniles enter adult territories during stressful foraging periods. Ecology 76:533-543.

Jordan, D.S. 1878. Manual of the Vertebrates of the Northern United States, Including the District East of the Mississippi River, and North of North Carolina and Tennessee, Exclusive of Marine Species. Second Edition, Revised, and Enlarged. Chicago: Jansen, McClung and Company. 407 pp.

Jung, R E., S. Droege, J. R. Sauer, and R.B. Landy. 2000. Evaluation of terrestrial and streamside salamander monitoring techniques at Shenandoah National Park. Environmental Monitoring and Assessment 63:65-79.

Juterbock, J.E. 1987. The nesting behavior of the dusky salamander, Desmognathus fuscus. II. Nest site tenacity and disturbance. Herpetologica 43:361-368.

Jutras, J. (ed.) 2003. Plan d’intervention sur les salamandres de ruisseaux du Québec, Direction du développement de la faune, Société de la faune et des parcs du Québec, Québec. 26 p.

Kamstra, J. 1991. Rediscovery of the Northern Dusky Salamander, Desmognathus f. fuscus in Ontario. Canadian Field-Naturalist 105:561-563.

Karam, M., pers. comm. 2017. Email exchange with A. Boutin. February 2017. Management Biologist, Ontario Ministry of Natural Resources and Forestry, Vineland Station, Ontario.

Karlin, A.A., and S.I. Guttman. 1981. Hybridization between Desmognathus fuscus and Desmognathus ochrophaeus (Amphibia: Urodela: Plethodontidae) in northeastern Ohio and northwestern Pennsylvania. Copeia 1981:371-377.

Karlin, A.A., and S.I. Guttman. 1986. Systematics and geographic isozyme variation in the Plethodontid salamander Desmognathus fuscus (Rafinesque). Herpetologica 42:283-301.

Keen, W.H. 1979. Feeding and activity patterns in the salamander Desmognathus ochrophaeus (Amphibia, Urodela, Plethodontidae). Journal of Herpetology 13(4):461-467.

Keen, W.H., and L.P. Orr. 1980. Reproductive cycle, growth, and maturation of northern female Desmognathus ochrophaeus. Journal of Herpetology 14:7-10.

Keitzer, C.S., and R.R. Goforth. 2013. Salamander diversity alters stream macroinvertebrate community structure. Freshwater Biology 58(10):2114-2125.

King, W. 1939. A survey of the herpetology of the Great Smoky Mountains National Park. American Midland Naturalist 21:531-582.

Knapp, S.M., C.A. Haas, D.N. Harpole, and R.I. Kirkpatrick. 2003. Initial effects of clearcutting and alternative silvicultural practices on terrestrial salamander abundance. Conservation Biology 17:752-762.

Kozak, K.H. and J.J. Wiens. 2006. Does Niche Conservatism Promote Speciation? A Case Study in North American Salamanders. Evolution 60(12):2604-2621.

Kozak, K.H., A. Larson, R.M. Bonett and L.J. Harmon. 2005. Phylogenetic analysis of ecomorphological divergence, community structure, and diversification rates in dusky salamanders (Plethodontidae: Desmognathus). Evolution 59(9):2000-2016.

Krzysik, A.J. 1979. Resource allocation, coexistence, and the niche structure of a streambank salamander community. Ecological Monographs 49:173-194.

Krzysik, A.J. 1980a. Trophic aspects of brooding behaviour in Desmognathus fuscus fuscus. Journal of Herpetology 14 (4):426-428.

Krzysik, A.J. 1980b. Microhabitat selection and brooding phenology of Desmognathus fuscus fuscus in western Pennsylvania. Journal of Herpetology 14:291-291.

Kucken, D.J., J.S. Davis, and J.W. Petranka. 1994. Anakeesta stream acidification and metal contamination: Effects on a salamander community. Journal of Environmental Quality 23:1311-1317.

Lancaster, J., A.G. Hildrew, and C. Gjerlov. 1996. Invertebrate drift and longitudinal transport processes in streams. Canadian Journal of Fisheries and Aquatic Sciences 53:572-582.

Larocque, M., G. Leroux, C. Madramootoo, F.-J. Lapointe, S. Pellerin, and J. Bonin. 2006. Mise en place d’un laboratoire naturel sur le mont Covey Hill (Québec, Canada). Vertigo – La revue électronique en sciences de l’environnement, Volume 7 (1). 11 p.

Larocque, M., L. Parrott, D. Green, M. Lavoie, S. Pellerin, J. Levison, P. Girard, and M.-A. Ouellet. 2013. Modélisation hydrogéologique et modélisation des populations de salamandres sur le mont Covey Hill: Perspectives pour la conservation des habitats en présence de changements climatiques. PACC26-Ouranos, Québec. May 2013. xii + 87 p.

Laurendeau, C., pers. comm. 2015. Email exchange with A. Boutin. October 2015. Wildlife technician, Ministère des Forêts, de la Faune et des Parcs, Secteur de la faune et des parcs, Québec, Québec.

Laurendeau, C., in preparation. Rapport d’inventaire de salamandres pourpres dans la région de l’Estrie en 2010 et dans les régions du Centre-du-Québec et de Chaudières-Appalaches en 2011. Québec. Ministère des Forêts, de la Faune et des Parcs, Secteur Faune Québec.

Laurendeau, C., in preparation. Rapport d’inventaire de salamandres pourpres à Saint-Robert-Bellarmin (Estrie) et aux Monts Foster, Glen et Bromont (Montérégie/Estrie) en 2012 au Québec. Ministère des Forêts, de la Faune et des Parcs, Secteur Faune Québec.

Logier, E.B.S. 1952. The Frogs, Toads and Salamanders of Eastern Canada. Clarke, Irwin, place of publication not identified.

Lowe, W.H. 2002. Landscape-scale spatial population dynamics in human-impacted stream systems. Environmental Management 30:225-233.

Lowe, W.H. 2003. Linking dispersal to local population dynamics: A case study using a headwater salamander system. Ecology 84:2145-2154.

Lowe, W. H. 2012. Climate change is linked to long-term decline in a stream salamander. Biological Conservation 145:48-53.

Lowe, W.H., and D.T. Bolger. 2002. Local and landscape-scale predictors of salamander abundance in New Hampshire headwater streams. Conservation Biology 16:183-193.

Lowe, W.H., K.H. Nilsow, and D.T. Bolger. 2004. Stage-specific and interactive effects of sedimentation and trout on a headwater stream salamander. Ecological Applications 14:64-172.

Lowe, W.H., G.E. Likens, and B.J. Cosentino. 2006a. Self-organisation in streams: the relationship between movement behaviour and body condition in a headwater salamander. Freshwater Biology 51:2052-2062.

Lowe, W.H., G.E. Likens, M.A. McPeek, and D.C. Buso. 2006b. Linking direct and indirect data on dispersal: isolation by slope in a headwater stream salamander. Ecology 87:334-339.

Lutterschmidt, W.I., G.A. Marvin, and V.H. Hutchison. 1994. Alarm response by a plethodontid salamander (Desmognathus ochrophaeus): Conspecific and heterospecific “Schreckstoff.” Journal of Chemical Ecology 20(11):2751-2759.

Marcum, C., Jr. 1994. Ecology and natural history of four plethodontid species in the Fernow Experimental Forest, Tucker County, West Virginia. Thesis, Marshall University, Huntington, West Virginia, USA. 254 pp.

Markle, T.M. 2006. Range limitations and phylogeography of stream salamanders in Québec and Labrador. A thesis submitted to McGill University in partial fulfillment of the requirements of the degree of Master of Science. Department of Biology, McGill University, Montréal, Québec, August 2006. 107 p.

Markle, T.M., and D.M. Green. 2005. Molecular Identification of Allegheny Mountain Dusky Salamanders, Desmognathus ochrophaeus, in Southern Ontario. Report for Ontario Ministry of Natural Resources (OMNR), Niagara, Ontario. 8 p.

Markle, T.M., and D.M. Green. 2006. Molecular Comparison of Allegheny Mountain Dusky Salamanders, Desmognathus ochrophaeus, in Southern Ontario and Western New York State. Report for Ontario Ministry of Natural Resources (OMNR), Niagara, Ontario. 7 p.

Markle, T.M., D.M. Green, A. Yagi, and W.F. Weller. 2006. Desmognathus ochrophaeus (Allegheny Mountain Dusky Salamander) in Ontario. Herpetological Review 37(4):482-483.

Markle, T.M., A.R. Yagi, and D.M. Green. 2013. Recovery Strategy for the Allegheny Mountain Dusky Salamander (Desmognathus ochrophaeus) and the Northern Dusky Salamander (Desmognathus fuscus) in Ontario. Recovery Strategy Series. Prepared for the Ontario Ministry of Natural Resources, Peterborough, Ontario. vi + 30 pp.

Marsh, D.M., G.S. Milam, N.P. Gorham, and N. G. Beckman. 2005. Forest roads as partial barriers to terrestrial salamander movement. Conservation Biology 19(6): 2004-2008.

Martof, B.S., and F.L. Rose. 1963. Geographic variation in southern populations of Desmognathus ochrophaeus. The American Midland Naturalist 69:377-425.

Marvin, G.A. 2003. Aquatic and terrestrial locomotor performance in a semiaquatic plethodontid salamander (Pseudotriton ruber): influence of acute temperature, thermal acclimation, and body size. Copeia 2003:704-713.

Marynick, S.P. 1971. Long term storage of sperm in Desmognathus fuscus from Louisiana. Copeia 1971:345-347.

Mead, L.S., and S.G. Tilley. 2000. Ethological isolation and variation in allozymes and dorsolateral pattern between parapatric forms in the Desmognathus ochrophaeus complex, in R.C. Bruce, R.G. Jaeger and L.D. Houck (ed.). The Biology of Plethodontid Salamanders, Kluer Academic, Plenum Publishers, New York, p.181-198.

Mead, L.S., and P.A. Verrell. 2002. Evolution of courtship behaviour patterns and reproductive isolation in the Desmognathus ochrophaeus complex. Ethology 108:403-427.

Milanovitch, J.R., W.E. Peterman, N.P. Nibbelink, and J.C. Maerz. 2010. Projected loss of a salamander diversity hotspot as a consequence of projected global climate change. PLoS ONE 5(8):e12189.

Ministère des Ressources naturelles et de la Faune du Québec. 2008. Protection des espèces menacées ou vulnérables en forêt publique - Les salamandres de ruisseaux: la salamandre pourpre (Gyrinophilus porphyriticus), la salamandre sombre des montagnes (Desmognathus ochrophaeus) et la salamandre sombre du Nord (Desmognathus fuscus). Faune Québec, Direction de l’expertise sur la faune et ses habitats. 38 p.

Ministère des Ressources Naturelles et de la Faune du Québec et Conservation de la Nature Canada. 2012. Inventaires et désignation de l'habitat légal de la salamandre sombre des montagnes. Technical Report. March 2012. 8 p.

Moore, A.L., C.E. William, T.H. Martin, and W.J. Moriarity. 2001. Influence of season, geomorphic surface and cover item on capture, size and weight of Desmognathus ochrophaeus and Plethodon cinereus in Allegheny Plateau riparian forests. The American Midland Naturalist 145:39-45.

Moore, C.M., and L.M. Sievert. 2001. Temperature-mediated characteristics of the dusky salamander (Desmognathus fuscus) of southern Appalachia. Journal of Thermal Biology 26(6):547-554.

Moriarty, J.J. (ed.). 2012. Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with comments regarding confidence in our understanding. 7th Edition. Herpetological Circular No 39. Society for the Study of Amphibians and Reptiles, St. Louis, Missouri.

Moseley, K.R., W.M. Ford, J.W. Edwards, and T.M. Shuler. 2008. Long-term partial cutting impacts on Desmognathus salamander abundance in West Virginia headwater streams. Forest Ecology and Management 254:300-307.

Mufti, S.A., and S.B. Simpson, Jr. 2005. Tail regeneration following autotomy in the adult salamander Desmognathus fuscus. Journal of Morphology 136(3):297-311.

Müller, K. 1954. Investigations on the organic drift in North Swedish streams. Republican Institute of Freshwater Resources Drottningholm 35:133-148.

Muncy B.L., S.J. Price, S.J. Bonner, and C.D. Barton. 2014. Mountaintop removal mining reduces stream salamander occupancy and richness in southeastern Kentucky (USA). Biological Conservation 180:115-121.

Munshi-South, J., Y. Zak, and E. Pehek. 2013. Conservation genetics of extremely isolated urban populations of the northern dusky salamander (Desmognathus fuscus) in New York City. PeerJ 1:e64.

Nadeau, S., pers. comm. 2010. Email exchange with A. Boutin. 2010. Senior Advisor, Fish Population Science, Fisheries and Oceans Canada, Government of Canada, Ottawa, Ontario.

Nash, C.W. 1908. Check list of the Batrachians and Reptiles of Ontario in Manual of Vertebrates of Ontario. Department of Education, Toronto. Warwick Bros. & Rutter, Limited, Printers, Toronto. 32 pp.

NatureServe. 2015. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Web site: [accessed July 2015].

NHIC. 2015. National Heritage Information Centre, Ontario Ministry of Natural Resources and Forestry.

Noël, S., M. Ouellet, P. Galois, and F.-J. Lapointe. 2007. Impact of urban fragmentation on the genetic structure of the eastern red-backed salamander. Conservation Genetics 8:599-606.

Noël-Boissonneault, S. 2009. Structure génétique de populations montréalaises de salamandres cendrées (Plethodon cinereus) et de salamandres à points bleus (Ambystoma laterale). Thèse présentée à la Faculté des études supérieures et postdoctorales en vue de l’obtention du grade de Philosophiae doctor (Ph.D.) en sciences biologiques. Département de sciences biologiques, Université de Montréal, June 2009. xxi + 147 p.

Olson, D.H., and K.L. Ronnenberg. 2014. Global Bd mapping project: 2014 update. FrogLog 22(3):17-21.

Organ, J.A. 1961. Studies of the local distribution, life history, and population dynamics of the salamander genus Desmognathus in Virginia. Ecological Monographs 31:189-220.

Orr, L.P. 1989. Desmognathus ochrophaeus (Cope), Mountain dusky salamander, in R. A. Pfingsten and F. L. Downs (ed). Salamanders of Ohio. Bulletin of the Ohio Biological Survey 7(2) College of Biological Sciences, The Ohio State University. Columbus, Ohio, p. 181-189.

Orr, L.P., and W.T. Maple. 1978. Competition avoidance mechanisms in salamander larvae of the genus Desmognathus. Copeia 1978:679-685.

Orser, P.N., and D.J. Shure. 1972. Effects of urbanization on the salamander, Desmognathus fuscus fuscus. Ecology 53:1148-1154.

Ouellet, M., P. Galois, and R. Pétel. 2004. Inventaire des amphibiens et des reptiles sur le mont Royal au cours de l’année 2004. Rapport scientifique réalisé pour la Ville de Montréal, Québec, 25 p.

Ouellet, M., P. Galois, R. Pétel, and C. Fortin. 2005. Les amphibiens et les reptiles des collines montérégiennes: enjeux et conservation. Le naturaliste Canadien - La société Provancher d’histoire naturelle du Canada 129:42-49.

Park, D., S.C. Hempleman, and C.R. Propper. 2001. Endosulfan exposure disrupts pheromonal systems in the red-spotted newt: a mechanism for subtle effects of environmental chemicals. Environmental Health Perspectives 109:669-673.

Pasachnik, S., and G.R. Ruthig. 2004. Versatility of habitat use in three sympatric species of plethodontid salamanders. Journal of Herpetology 38 (3):434-437.

Pauley, T.K., and M.B. Watson. 2005. Desmognathus ochrophaeus (Cope, 1859) Allegheny Mountain Dusky Salamander. p. 716-719 in M. Lannoo (ed.). Amphibian Declines: The Conservation Status of United States Species, University of California Press, Berkeley, California.

Pellerin, S., and C. Lavoie. 2003. Reconstructing the recent dynamics of mires using a multi-technique approach. Journal of Ecology 97:1008-1021.

Pendlebury, G.B. 1973. Distribution of the dusky salamander Desmognathus fuscus fuscus (Caudata: Plethodontidae) in Québec, with special reference to a population from St. Hilaire. The Canadian Field Naturalist 87:131-136.

Peterman, W.E., J.A. Crawford, and R.D. Semlitsch. 2008. Productivity and significance of headwater streams: population structure and biomass of the Black-bellied Salamander (Desmognathus quadramaculatus). Freshwater Biology 53:347-357.

Petranka, J.W. 1983. Fish predation: a factor affecting the spatial distribution of a stream-breeding salamander. Copeia 1983:624–628.

Petranka, J.W. 1994. Response to impact of timber harvesting on salamanders. Conservation Biology 8:302-304.

Petranka, J.W. 1998. Salamanders of the United States and Canada. Smithsonian Institution Press, Washington, D.C. xvi + 587 p.

Petranka, J.W., and S.S. Murray. 2001. Effectiveness of removal sampling for determining salamander density and biomass: a case study in an Appalachian streamside community. Journal of Herpetology 35:36-44.

Petranka, J.W., and C.K. Smith. 2005. A functional analysis of streamside habitat use by southern Appalachian salamanders: Implications for riparian forest management. Forest Ecology and Management 210:443-454.

Petranka, J.W., E.M. Harp, C.T. Holbrook, and J.A. Hamel, 2007. Long-term persistence of amphibian populations in a restored wetland complex. Biological Conservation 138(3):371-380.

Pfingsten, R.A. 1966. The reproduction of Desmognathus ochrophaeus ochrophaeus in Ohio, Master of Science thesis, Kent State University, Ohio.

Pouliot, D., and J.-M. Vallières. 2007. Quelques mentions d'intérêt concernant l'herpétofaune de la Mauricie. Le Naturaliste Canadien 131(2):44-50.

Pouliot, D., J.-F. Desroches, and D. Banville. 2007. Inventaire herpétologique de la région de la Capitale-Nationale en 2002. Le Naturaliste Canadien 131(1):34-40.

Power, M.E., R.J. Stout, C.E. Cushing, P.P. Harper, F.R. Hauser, W.J. Matthews, P.B. Moyle, B. Statzner, and I.R. Wais De Badgen. 1988. Biotic and abiotic communities. Journal of the North American Benthological Society 7:1-25.

Price, S.J., M.E. Dorcas, A.D. Gallant, R.W. Klaver, and J.D. Willson. 2006. Three decades of urbanization: Estimating the impact of land-cover change on stream salamander populations. Biological Conservation 133:436-441.

Price, S.J., R.A. Browne, and M.E. Dorcas. 2012. Evaluating the effect of urbanisation on salamander abundances using a before-after control-impact design. Freshwater Biology 57:193-203.

Rankin, J.S. 1937. An ecological study of parasites of some North Carolina salamanders. Ecological Monographs 7(2):169-269.

Rhoads, S.N. 1895. Contributions to the zoology of Tennessee. No. 1, Reptiles and amphibians. Proceedings of the Academy of Natural Sciences of Philadelphia 47:376-407.

Rioux, S. 2009. pers. comm. Email exchange with A. Boutin. August 2009. Biologist, Species at Risk Recovery Unit, Environment Canada, Canadian Wildlife Service, Québec City, Québec.

Rissler, L.J., and D.R. Taylor. 2003. The phylogenetics of desmognathine salamander populations across the southern Appalachians. Molecular Phylogenetics and Evolution 27:197-211.

Rothermel B.B., E.R. Travis, D.L. Miller, R.L. Hill, J.L. McGuire, and M.J. Yabsley. 2013. High occupancy of stream salamanders despite high Ranavirus prevalence in a southern Appalachian watershed. EcoHealth 10:184-189.

Roudebush, R.E. 1988. A behavioral assay for acid sensitivity in two desmognathine species of salamanders. Herpetologica 44:392-395.

Roudebush, R.E, and D.H. Taylor. 1987. Behavioral interactions between two desmognathine salamander species: Importance of competition and predation. Ecology 68:1453-1458.

Rouse, J.D., C.A. Bishop, and J. Struger. 1999. Nitrogen pollution: an assessment of its threat to amphibian survival. Environmental Health Perspectives 107:799-803.

Russell, R.W., S.J. Hecnar, and G.D. Hafner. 1995 Organochlorine pesticide residues in southern Ontario Spring peepers. Environmental Toxicology and Chemistry 14:815-817.

Rutherford, A., G. Leroux, C. Senecal, A. Boutin, and C. Madramootoo. 2004. Using quantitative methods to gather small stream flow data for habitat characterization. Société de conservation et d’aménagement du bassin de la rivière Châteauguay (SCABRIC), Québec, 20 p.

Schalk, C.M., and T.M. Luhring. 2010. Vagility of Aquatic Salamanders: Implications for Wetland Connectivity. Journal of Herpetology 44 (1):104-109.

Scheffers, B., and C. Paszkowski. 2012. The effects of urbanization on North American amphibian species: Identifying new directions for urban conservation. Urban Ecosystems 15:133-147.

Schmidt, K.P. 1953. A check list of North American amphibians and reptiles. 6th ed. American Society of Ichthyologists and Herpetologists. University of Chicago Press, Chicago, Illinois. 280 p.

Shaffer, F., and Y. Bachand. 1989. Nouvelles localités pour la salamandre pourpre au Québec. Naturaliste canadien 116:279-281.

Shannon, C.B. 2000. Stream salamander response to timber harvest and interstitial refuge selection. Undergraduate Thesis. Dartmouth College, Hanover, New Hampshire, USA.

Sharbel, T.F., and J. Bonin. 1992. Northernmost Record of Desmognathus ochrophaeus: Biochemical Identification in the Chateauguay River Drainage Basin, Québec. Journal of Herpetology 26:505-508.

Sharbel, T.F., J. Bonin, L.A. Lowcock, and D.M. Green. 1995. Partial genetic compatibility and unidirectional hybridization in syntopic populations of the salamanders Desmognathus fuscus and D. ochrophaeus. Copeia 1995:466-469.

Shealy, R.M. 1975. Factors influencing activity in the salamanders Desmognathus ochrophaeus and D. monticola (Plethodontidae). Herpetologica 31:94-102.

Shoemaker, V.H., S.S. Hillman, S.D. Hilar, D.C. Jackson, L L. Mcclanahan, P.C. Withers, and M.L. Wygoda. 1992. Exchange of water, ions, and respiratory gases in terrestrial amphibians, pp. 183-205 in M.E. Feder, and W.W. Burggren (ed.). Environmental Physiology of the Amphibians. The University of Chicago Press, Chicago, Illinois.

Sih, A., L.B. Kats, and R.D. Moore. 1992. Effects of predatory sunfish on the density, drift and refuge use of stream salamander larvae. Ecology 73:1418-1430.

Smith, W.H. 1877. The Tailed Amphibians, Including the Caecilians. A Thesis Presented to the Faculty of Michigan University, Detroit, Herald Publishing House.

Snider, A.T., and J.K. Bowler. 1992. Longevity of reptiles and amphibians in North American collections, 2nd ed. Society for the Study of Amphibians and Reptiles, Herpetological Circular No. 21. SSAR Publications. 40 p.

Snodgrass, J.W., D.C. Forester, M. Lahiti, and E. Lehman. 2007. Dusky salamander (Desmognathus fuscus) nest-site selection over multiple spatial scales. Herpetologica 63 4):441-449.

Sophocleous, M. 2000. From safe yield to sustainable development of water resources – the Kansas experience. Journal of Hydrology 235:27-43.

Southerland, M.T. 1986a. The effects of variation in streamside habitats on the composition of mountain salamander communities. Copeia 1986:731-741.

Southerland, M.T. 1986b. Behavioral interactions among four species of the salamander genus Desmognathus. Ecology 67:175-181.

Southerland, M.T. 1986c. Coexistence in three congeneric salamanders: The importance of habitat and body size. Ecology 67:721-728.

Southerland, M.T., R.E. Jung, D.P. Baxter, I.C. Chellman, G. Mercurio, and J.H. Volstad. 2004. Stream salamanders as indicators of stream quality in Maryland, U.S.A. Applied Herpetology 2:23-46.

Spight, T.M. 1967. The water economy of salamanders: Exchange of water with the soil. Biological Bulletin 132:126-132.

Spight, T.M. 1968. The water economy of salamanders: evaporative water loss. Physiological Zoology 41:195-203.

Spotila, J.R. 1972. Role of temperature and water in the ecology of lungless salamanders. Ecological Monographs 42:95-125.

Spotila, J.R., and E.N. Berman. 1976. Determination of skin resistance and the role of the skin in controlling water loss in amphibians and reptiles. Comparative Biochemistry and Physiology 55(4):407-411.

Tessier, N., pers. comm. 2015. Email exchange with A Boutin. September 2015. Biologist, Ministère des Forêts, de la Faune et des Parcs, Secteur des opérations régionales, Direction de la gestion de la faune, Longueuil, Québec.

Thompson, B., B. Hindley, and C. DeVito. 2012. Findings of flow monitoring near salamander habitat adjacent to the OPG SAB PGS reservoir during the comprehensive geotechnical investigation (CGI). Technical memorandum. Golder Associates Ltd. Mississauga, Ontario. 35 p.

Thompson, B., A. Beal, and M. Rawlings. 2014. On-going monitoring of the salamander habitats in the vicinity of the Ontario Power Generation Sir Adam Beck Generating Station. Technical memorandum. Golder Associates Ltd. Mississauga, Ontario. 32 p.

Thorson, T.B., and A. Svihla. 1943. Correlation of the habitats of amphibians with their ability to survive the loss of body water. Ecology 24:374-381.

Tilley, S.G. 1969. Variation in the dorsal pattern of Desmognathus ochrophaeus at Mt. Mitchell, North Carolina, and elsewhere in the southern Appalachian Mountains. Copeia 1969:161-175.

Tilley, S.G. 1972. Aspects of parental care and embryonic development in Desmognathus ochrophaeus. Copeia 1972:532-540.

Tilley, S.G. 1973. Observations on the larval period and female reproductive ecology of Desmognathus ochrophaeus (Amphibian: Plethodontidae) in western North Carolina. American Midland Naturalist 89(2):394-407.

Tilley, S.G. 1974. Structures and dynamics of populations of the salamander Desmognathus ochrophaeus cope in different habitats. Ecology 55:808-817.

Tilley, S.G. 1980. Life histories and comparative demography of two salamander populations. Copeia 1980:806-821.

Tilley, S. G. 1997. Patterns of genetic differentiation in Appalachian desmognathine salamanders. Journal of Heredity 88:305–315.

Tilley, S.G. 2000. The systematics of Desmognathus imitator, in R.C. Bruce, R.G. Jaeger, and L.D. Houck (ed). The biology of plethodontid salamanders, Kluwer Academic/Plenum Publishers, New York, p 121-147.

Tilley, S.G., and J.A. Hausman. 1976. Allozymic variation and occurrence of multiple inseminations in populations of the salamander Desmognathus ochrophaeus. Copeia 1976:734-741.

Tilley, S.G., and P.M. Schwerdtfeger. 1981. Electrophoretic variation in Appalachian populations of the Desmognathus fuscus complex (Amphibia: Plethodontidae). Copeia 1981:109-119.

Tilley, S.G., and M.J. Mahoney. 1996. Patterns of genetic differentiation in salamanders of the Desmognathus ochrophaeus complex (Amphibia: Plethodontidae). Herpetological Monographs 10:1-42.

Tilley, S.G., P.A. Verrell, and S.J. Arnold. 1990. Correspondence between sexual isolation and allozyme differentiation: a test in the salamander Desmognathus ochrophaeus. Proceedings of the National Academy of Sciences 87:2715-2719.

Trottier, J. 2006. Impact de l’exploitation forestière sur la richesse et l’abondance des amphibiens de la forêt boréale méridionale du Bas-Saint-Laurent. Mémoire de maîtrise, Université du Québec à Rimouski, Rimouski, Québec. 97 p.

Turner, M.A. 2004. Some Water Quality Threats to the Barton Springs Salamander at Low Flows. Watershed Protection Development Review. Water Resource Evaluation Section, Environmental Resource Management Division, City of Austin, Austin, Texas. 11 p.

Uhler, F.M., C. Cottom, and T.E. Clarke. 1939. Food of snakes of the George Washington National Forest, Virginia. Transactions of the North American Wildlife Conference 4:605-622.

Uzendoski, K., and P. Verrell. 1993. Sexual incompatibility and mate-recognition systems: a study of two species of sympatric salamanders (Plethodontidae). Animal Behaviour 46:267-278.

Uzendoski, K.E., E. Maksymovvitch, and P. Verrell. 1993. Do the risk of predation and intermale competition affect courtship behavior in the salamander Desmognathus ochrophaeus? Behavioral Ecology and Sociobiology 32:421-427.

van Kote G. 2009. La Montagne décapitée. Le Monde, September 7, 2009. Web site:[accessed November 2016].

Verrell, P.A. 1990. Sexual compatibility among plethodontid salamanders: Tests between Desmognathus apalachicolae, and D. ochrophaeus and D. fuscus. Herpetologica 46:415-422.

Verrell, P.A. 1991. Insemination temporarily inhibits sexual responsiveness in female salamanders (Desmognathus ochrophaeus). Behaviour 119(1-2):51-64.

Verrell, P.A. 1994. Evidence against a role for experience in the maintenance of sexual incompatibility between sympatric salamanders. Herpetologica 50(4):475-479.

Verrell, P.A., and M. Mabry. 2000. The Courtship of Plethodontid Salamanders: form, function and phylogeny. pp. 371-380 in R.C. Bruce, R.G. Jaeger, and L.D. Houck (eds.). The Biology of Plethodontid Salamanders. Springer, New York.

Ward, R.L., J.T. Anderson, and J. Petty. 2008. Effects of road crossings on stream and streamside salamanders. The Journal of Wildlife Management 72(3):760-771.

Waters, T.F. 1995. Sediment in streams: sources, biological effects and controls. American Fisheries Society Monograph 7, Bethesda, Maryland. 251 p.

Weber, J.A. 1928. Herpetological observations in the Adirondack Mountains, New York. Copeia 169:106-112.

Weller, W.F. 1977. Distribution of stream salamanders in southwestern Québec. Canadian Field-Naturalist 91:299-303.

Weller, W.F. 2010. Results of field investigations for dusky salamanders (Desmognathus) in [name removed] Creek, R.M. Niagara in 2010. Report prepared by Environment Division, Hydro Business, Ontario Power Generation for Niagara Plant Group, Hydro Business, Ontario Power Generation. December, 2010.

Weller, W.F. 2011. Results of field investigations for dusky salamanders (Desmognathus) in [name removed] Creek, R.M. Niagara in 2011. Report prepared by Environment Division, Hydro Business, Ontario Power Generation for Niagara Plant Group, Hydro Business, Ontario Power Generation. December, 2011.

Weller, W.F. 2012. Results of field investigations for dusky salamanders (Desmognathus) in [name removed] Creek, R.M. Niagara in 2012. Report prepared by Commercial Operations & Environment, Environment Division, Ontario Power Generation for Niagara Plant Group, Hydro-Thermal Operations, Ontario Power Generation. November, 2012. 31 pp.

Weller, W.F. 2013. Results of field Iivestigations for dusky salamanders (Desmognathus) in [name removed] Creek, R.M. Niagara in 2013. Report prepared by Commercial Operations & Environment, Environmental Services Division, Ontario Power Generation for Niagara Plant Group, Hydro-Thermal Operations, Ontario Power Generation. November, 2013. 21 pp.

Weller, W.F., pers. comm. 2015. Email exchange with A. Boutin. June 2015. Senior Environmental Scientist (Ret.), Ontario Power Generation, Niagara-on-the-Lake, Ontario; currently Co-chair, Ontario Dusky Salamander Recovery and Implementation Team.

Weller, W.F., and J.E. Cebek. 1991a. Geographic Distribution: Desmognathus fuscus fuscus. Herpetological Review 22(1):23.

Weller, W.F., and J.E. Cebek. 1991b. Geographic Distribution: Eurycea bislineata. Herpetological Review 22(1):23-24.

Weller, W.F., and J.E. Cebek. 1991c. Geographic Distribution: Gyrinophilus porphyriticus porphyriticus. Herpetological Review 22(1):24.

Welsh, H.H., Jr., and L.M. Ollivier. 1998. Stream amphibians as indicators of ecosystem stress: a case study from California's redwoods. Ecological Applications 8(4):1118-1132.

Whiteman, H.H., and S.A. Wissinger. 1991. Differences in the antipredator behavior of three plethodontid salamanders to snake attack. Journal of Herpetology 25:352-355.

Whitford, W.G., and V.H. Hutchison. 1967. Body size and metabolic rate in salamanders. Physiological Zoology 40:127-133.

Wilson, J. D., and M.E. Dorcas. 2003. Effects of habitat disturbance on stream salamanders: implications for buffer zones and watershed management. Conservation Biology 17:763-771.

Wood, J.T., and F.E. Wood. 1955. Notes on the nests and nesting of the Carolina Mountain Dusky Salamander in Tennessee and Virginia. Journal of the Tennessee Academy of Science 38:36-39.

Wood, P.B., and J.M. Williams. 2013. Impact of valley fills on streamside salamanders in Southern West Virginia. Journal of Herpetology 47:119-125.

Wyman, R.L. 1988. Soil acidity and moisture and the distribution of amphibians in five forests of south-central New York. Copeia 1988:394-399.

Yagi, A., pers.comm. 2015. Email exchange with A. Boutin. June 2015. Management Biologist (Ret.), Ontario Ministry of Natural Resources and Forestry, Guelph District, Vineland Station, Ontario; currently Co-chair, Ontario Dusky Salamander Recovery and Implementation Team.

Yagi, A.R., and R. Tervo. 2008. Species at Risk Habitat Mapping for the Northern Dusky Salamander (Desmognathus fuscus) – A Test of Draft Habitat Mapping Guidelines. Ontario Ministry of Natural Resources. 12 p.

Biographical summary of report writers

Anaïs Boutin completed a master’s degree in biology at the Université de Montréal in 2006. Her thesis focused on determining the habitat selection of a community of stream salamanders from Covey Hill, Québec, comprising five species and Desmognathus ochrophaeus × D. fuscus hybrids. Her thesis work also focused on the development of molecular methods for identifying these hybrids and their parental species. Anaïs Boutin is the coordinator of the Québec stream salamander recovery team, and a member of the Ontario Dusky Salamander Recovery and Implementation Team and the Allegheny Mountain Dusky Salamander national recovery team. She is involved in the conservation of wildlife species and natural environments and works as a biologist in recovery efforts for species at risk.

Collections examined

No collections were examined as part of the preparation of this status report on Allegheny Mountain Dusky Salamander in Canada.

Appendix 1. Extent of occurrence (EOO) and index of area of occupancy (IAO) calculations for the Appalachian population of Allegheny Mountain Dusky Salamander

Appendix 2. [sensitive information removed.]

Appendix 3. Localities surveyed for Allegheny Mountain Dusky Salamander in Québec from 1990 to 2015 (Source: CDPNQ 2015)

Appendix 4. [sensitive information removed.]

Appendix 5. Threats calculator results for Allegheny Mountain Dusky Salamander, Appalachian population

Threats assessment worksheet

Species or ecosystem scientific name:

Desmognathus ochrophaeus - Appalachian (Adirondack) DU

Element ID:

not applicable

Elcode:

not applicable

Date:

18/07/2017

Assessor(s):

Kristiina Ovaska (facilitator), Bev McBride (COSEWIC Secretariat), Anaïs Boutin, Chris Edge, Wayne Weller, David Lesbarrères, Lyne Bouthillier, Sylvain Giguère, Carine Deland, Valerie René, Christina Rohe, Joe Crowley, Daniel Vervoort, Tom Herman

References:

Draft COSEWIC status report (March 2017)

Assigned overall threat impact:

BC = High - Medium

Impact adjustment reasons:

not applicable

Overall threat comments:

Generation time: 5-7 years; scores in red text were adjusted based on review comments from participants after the conference call

Appendix 6. Threats calculator results for Allegheny Mountain Dusky Salamander, Carolinian population.

Threats assessment worksheet

Species or ecosystem scientific name:

Desmognathus ochrophaeus - Appalachian Carolinian DU

Element ID:

not applicable

Elcode:

not applicable

Date:

18/07/2017

Assessor(s):

Kristiina Ovaska (facilitator), Bev McBride (COSEWIC Secretariat), Anaïs Boutin, Chris Edge, Wayne Weller, David Lesbarrères, Christina Rohe, Joe Crowley, Daniel Vervoort, Tom Herman

References:

Draft COSEWIC status report (March 2017)

Assigned overall threat impact:

A = Very High

Impact adjustment reasons:

not applicable

Overall threat comments:

Generation time 5 - 7 years

Classification of Threats adopted from IUCN-CMP, Salafsky et al. (2008). 

Appendix 7. Parcels containing critical habitat of Allegheny Mountain Dusky Salamander, Great Lakes / St. Lawrence population (Appalachian population in this report), identified by Environment Canada (2014).

Appendix 8. Observations of salamanders (BORAQ 2015) and protected areas at Covey Hill based on information obtained from Nature Conservancy Canada