Blanchard’s Cricket Frog (Acris blanchardi): COSEWIC Addendum 2024

Official title: COSEWIC Addendum on the Blanchard’s Cricket Frog (Acris blanchardi) in Canada 2024

Committee on the status of Endangered Wildlife in Canada (COSEWIC)

Extirpated

2024

COSEWIC assessment summary

Assessment summary - May 2024

Common name

Blanchard’s Cricket Frog

Scientific name

Acris blanchardi

Status

Extirpated

Reason for designation

This small tree-frog is widespread in the eastern United States, along shorelines of lakes, ponds, and streams with dense aquatic vegetation. It was only known in Canada from two places in southern Ontario (Point Pelee and Pelee Island), and was last confirmed in 1977 on Pelee Island. The presence of this species can be readily confirmed by its distinctive, loud calls in suitable habitat during the breeding season. However, despite many intensive searches and citizen science programs in previously-occupied or apparently suitable habitat, there have been no reliable observations since the 1977 sighting. Thus, there is sufficient information to conclude that no individuals of this wildlife species remain in Canada.

Occurrence

Ontario

Status history

Designated Endangered in April 1990. Status re-examined and confirmed in May 2001 and May 2011. Status re-examined and designated Extirpated in May 2024.

COSEWIC preface

Since the previous status assessment, no new information has come to light that suggests that any population or individual Blanchard's Cricket Frog (Acris blanchardi) remains in Ontario. The Committee on the Status of Species at Risk in Ontario (COSSARO) declared Blanchard's Cricket Frog extirpated in 2011. The last confirmed observation in Canada was 47 years ago and, while several researchers have conducted active searches in known or suitable Cricket Frog habitat, none of them have seen or heard any convincing evidence of persistence since the previous status assessment. Consequently, Blanchard's Cricket Frog meets COSEWIC’s guidelines for Extirpated because there is sufficient information to document that no individuals of the wildlife species remain alive.

COSEWIC addendum

Acris blanchardi

Blanchard’s Cricket Frog

Rainette grillon de Blanchard

Range of occurrence in Canada (province/territory/ocean): ON

Current COSEWIC assessment

Status category:

Extirpated

Date of last assessment:

May 2024

This small tree-frog is widespread in the eastern United States, along shorelines of lakes, ponds, and streams with dense aquatic vegetation. It was only known in Canada from two places in southern Ontario (Point Pelee and Pelee Island), and was last confirmed in 1977 on Pelee Island. The presence of this species can be readily confirmed by its distinctive, loud calls in suitable habitat during the breeding season. However, despite many intensive searches and citizen science programs in previously-occupied or apparently suitable habitat, there have been no reliable observations since the 1977 sighting. Thus, there is sufficient information to conclude that no individuals of this wildlife species remain in Canada.

Criteria applied at last assessment:

Not applicable

Evidence (indicate as applicable)

Wildlife species

Change in eligibility, taxonomy or designatable units:

No

Explanation:

Not applicable

Range

Change in Extent of Occurrence (EO):

No

Change in Index of Area of Occupancy (IAO):

No

Change in number of known or inferred current locations:

No

Significant new survey information

Yes

Explanation:

Not applicable

Population information

Change in number of mature individuals:

No

Change in population trend:

No

Change in severity of population fragmentation:

No

Change in trend in area and/or quality of habitat:

No

Significant new survey information:

Yes

Explanation:

Extensive surveys have been conducted at suitable and known Blanchard's Cricket Frog sites. Pelee Island Bird Observatory (PIBO) and the Toronto Zoo conducted a remote survey using 12 automated sound recorders placed around Pelee Island at sites deemed to be suitable habitats for Blanchard’s Cricket Frog. While there is potential but inconclusive evidence of calls that may have been made by Blanchard’s Cricket Frog, the report suggests that Blanchard’s Cricket Frog persistence in the areas surveyed was “unlikely” with “no obvious recordings of their calls” (Henderson 2012). Amphibian (salamander) surveys were conducted from 2015 to 2021 on Pelee Island (excluding 2020 because of COVID). One- to two-week-long trips were conducted each month from March to August at a variety of wetlands, including eight with historical occurrences of Blanchard's Cricket Frog (Hossie pers. comm. 2022). Reptile (specifically Blue Racer [Coluber constrictor foxii]) surveys have brought many surveyors with knowledge of Blanchard's Cricket Frog to Pelee Island during the breeding season, although effort in the correct habitat is difficult to determine (Hathaway pers. comm. 2022; Wolfe pers. comm. 2022). Citizen science programs such as the Ontario Reptile and Amphibian Atlas have also failed to produce any observations (Choquette and Jolin 2018). No sightings have been reported to iNaturalist or to the Ontario Natural Heritage Information Centre. There are no recent collections (nothing since the early 1970s) at the Museum of Nature.

Threats

Change in nature and/or severity of threats:

No

Explanation:

Not applicable

Protection

Change in effective protection:

No

Explanation:

Not applicable

Rescue effect

Change in evidence of rescue effect:

No

Explanation:

Not applicable

Quantitative analysis

Change in estimated probability of extirpation:

Yes

Details:

Not applicable

Summary and additional considerations

Blanchard's Cricket Frog remains widespread and common/abundant in places across its US range but has declined significantly, especially in the northern portion of its range (Gray and Brown 2005). The call is distinctive and obvious and, given the species’ limited geographic range in Canada, the call should be detectable during the breeding season (early June to late July; COSEWIC 2001; COSEWIC 2011; Environment Canada 2011).

The species has not been confirmed on the Ontario mainland since 1961 (COSEWIC 2001; COSEWIC 2011; Environment Canada 2011). It was last confirmed from Pelee Island in 1977 (Oldham and Campbell 1990); however, there are unconfirmed records from the 1990s (Kellar et al. 1997; see Environment Canada 2011 and Oldham 2011 for a complete list of observations). Records were considered unconfirmed if there were no photographs, audio recordings of calling frogs, or voucher specimens, and subsequent searches at these locations yielded no further records.

The Committee on the Status of Species at Risk in Ontario (COSSARO 2011) declared Blanchard's Cricket Frog extirpated in 2011 based on the lack of observations despite extensive search effort.

Extensive wildlife surveys conducted from 2015 to 2021 on Pelee Island (Hathaway pers. comm. 2022; Hossie pers. comm. 2022; Wolfe pers. comm. 2022) and extensive citizen science programs (Choquette and Jolin 2018) have failed to produce a reliable observation since the previous status assessment. Given the short lifespan (Dodd 2013), widespread population declines, and tiny fragmented range in Canada and given that there is no possibility of rescue effect from the US, it is extremely unlikely that Blanchard's Cricket Frog persists in Canada.

Acknowledgements and authorities contacted

Thomas Hossie
Assistant Professor
Biology Department
Trent University
Peterborough, ON

James Kamstra
Senior Ecologist with AECOM
Durham Region, ON

Ryan Wolfe
MSc Student
Department of Ecology and Evolutionary Biology
University of Toronto
Hamilton, ON

Jeff Hathaway
Scales Nature Park
Oro-Medonte, ON

Jill Crosthwaite
Coordinator, Conservation Biology, Southwestern Ontario
Nature Conservancy of Canada
Pelee Island, ON

Suzanne Friemann
Executive Director
Pelee Island Bird Observatory
Windsor, ON

Sumiko Onishi
Chief Bander
Pelee Island Bird Observatory
Pelee Island, ON

Information sources

Choquette, J.D., and E.A. Jolin. 2018. Checklist and status of the amphibians and reptiles of Essex County, Ontario: a 35 year update. Canadian Field-Naturalist 132:176-190.

COSEWIC. 2001. COSEWIC assessment and update status report on the Northern Cricket Frog Acris crepitans in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. v + 14 pp. (https://species-registry.canada.ca/index-en.html#/documents/2254).

COSEWIC. 2011. COSEWIC status appraisal summary on the Blanchard’s Cricket Frog Acris blanchardi in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi pp. (https://species-registry.canada.ca/index-en.html#/documents/2282).

COSSARO. 2011. Candidate Species at Risk Evaluation for Blanchard's Cricket Frog (Acris blanchardi). Committee on the Status of Species at Risk in Ontario (COSSARO), 5 pp.

Dodd, C.K. 2013. Frogs of the United States and Canada, 2-vol. set (Vol. 1). Johns Hopkins University Press. Baltimore, Maryland.

Environment Canada. 2011. Recovery Strategy for the Blanchard’s Cricket Frog (Acris blanchardi) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. v + 21 pp.

Gray, H.G., and L.E. Brown. 2005. Decline of Northern Cricket Frogs (Acris crepitans). Pp 47-54. in M. Lanoo (ed.). Amphibian Declines: The Conservation Status of United States Species, University of California Press, Oakland, California.

Hathaway, J. pers. comm. 2022. Personal communication to N. Cairns. Scales Nature Park, 7 April 2022.

Henderson, R. 2012. Pelee Island Blanchard’s Cricket Frog Project: Data Analysis. Unpublished report from the Pelee Island Bird Observatory (PIBO).

Hossie, T. pers. comm. 2022. Personal communication to N. Cairns. Trent University, 7 April 2022

Kellar, T., G. Waldron, C. Bishop, J. Bogart, D.A. Kraus, M. McLaren, and M. Oldham. 1997. National Recovery Plan for Blanchard’s Cricket Frog. Report No. 16. Recovery of Nationally Endangered Wildlife Committee, Ottawa, Ontario. 19 pp.

Oldham, M.J., and C.A. Campbell. 1990. Status Report on the Northern Cricket Frog Acris crepitans blanchardi in Canada. COSEWIC. Unpublished report. 31 pp.

Oldham, M.J. 2011. Notes on the status of Blanchard’s Cricket Frog (Acris blanchardi) in Ontario. Unpublished manuscript May 2011. 5 pp.

Wolfe, R. pers. comm. 2022. Personal communication to N. Cairns. University of Toronto, 7 April 2022.

Author of addendum

Nicholas A. Cairns
Curator, of Non-avian Vertebrates
Royal Alberta Museum
Edmonton, AB

Technical summary

Acris blanchardi

Blanchard's Cricket Frogs

Rainette grillon de Blanchard

Range of occurrence in Canada: ON

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 (2008) is being used)

1 to 2 years

Is there an inferred continuing decline in number of mature individuals?

Not applicable (no recent records)

Estimated percent of continuing decline in total number of mature individuals within 2 generations.

Not applicable

Inferred percent reduction in total number of mature individuals over the last 3 generations.

Not applicable

Suspected percent reduction in total number of mature individuals over the next 3 generations.

Not applicable

Inferred percent reduction in total number of mature individuals over any 3 generations period, over a time period including both the past and the future.

Not applicable

Are the causes of the decline clearly reversible and understood and ceased?

Not applicable

Are there extreme fluctuations in number of mature individuals?

Not applicable

Extent and occupancy information

Estimated extent of occurrence

0 km²

Index of area of occupancy (IAO)

(Always report 2x2 grid value).

0 km²

Is the population severely fragmented?

Not applicable

Number of locations

0

Is there an inferred continuing decline in extent of occurrence?

Not applicable

Is there an inferred continuing decline in index of area of occupancy?

Not applicable

Is there an inferred continuing decline in number of populations?

Not applicable

Is there an inferred continuing decline in number of locations?

Not applicable

Is there an inferred continuing decline in area, extent and/or quality of habitat?

Not applicable

Are there extreme fluctuations in number of populations?

Not applicable

Are there extreme fluctuations in number of locations?

Not applicable

Are there extreme fluctuations in extent of occurrence?

Not applicable

Are there extreme fluctuations in index of area of occupancy?

Not applicable

Subpopulation

N Mature Individuals

Total

0

Quantitative analysis

Probability of extinction in the wild is at least 20% within 5 generations.

Not applicable

Threats (actual or imminent, to populations or habitats)

Historically, loss of habitat and pollution from multiple anthropogenic sources, potential climate shifts, chytridiomycosis, range expansion of large fish, invasive non-native Phragmites australis (Common Reed) reeds in breeding sites, and trophic shift/cascades.

Rescue effect (immigration from outside Canada)

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

Ohio (S2 – imperilled); Michigan (S2 – imperilled); immigration/rescue is impossible given the isolation by water and/or agriculture between persistent populations in the US and the formerly occupied sites in Canada.

Is immigration known or possible?

No

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Unknown

Are conditions deteriorating in Canada?

Yes

Are conditions for the source (that is, outside) population deteriorating?

Yes

Is rescue from outside populations likely?

No

Data sensitive species

Is this a data sensitive species?

No

Current status

COSEWIC:

Extirpated

Year assessed:

2024

Status history:

Designated Endangered in April 1990.
Status re-examined and confirmed in May 2001 and May 2011. Status re-examined and designated Extirpated in May 2024.

Criteria: Not applicable

Reasons for designation:

This small tree-frog is widespread in the eastern United States, along shorelines of lakes, ponds, and streams with dense aquatic vegetation. It was only known in Canada from two places in southern Ontario (Point Pelee and Pelee Island), and was last confirmed in 1977 on Pelee Island. The presence of this species can be readily confirmed by its distinctive, loud calls in suitable habitat during the breeding season. However, despite many intensive searches and citizen science programs in previously-occupied or apparently suitable habitat, there have been no reliable observations since the 1977 sighting. Thus, there is sufficient information to conclude that no individuals of this wildlife species remain in Canada.

Applicability of criteria

Criteria A:
Not applicable. Reduction in the number of mature individuals over the last ten years cannot be calculated, as no mature individuals have been observed in Canada since 1977.

Criteria B:
Not applicable. EOO and IAO cannot be calculated, as no mature individuals have been observed in Canada since 1977.

Criteria C:
Not applicable. There is no continuing decline, as no mature individuals have been observed in Canada since 1977.

Criteria D:
Not applicable. The total number of mature individuals cannot be calculated, as no mature individuals have been observed in Canada since 1977.

Criteria E:
Not applicable. Analysis not conducted, as no mature individuals have been observed in Canada since 1977.

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 (2024)

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)^*

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)^**

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

Data Deficient (DD)^***

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.

^* Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.
^** Formerly described as “Not In Any Category”, or “No Designation Required.”
^*** 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.

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