COSEWIC Assessment and Addendum on the Black-footed Ferret Mustela nigripes in Canada – 2009

Extirpated 2009

COSEWIC -- Committee on the Status of Endangered Wildlife in Canada

COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:

COSEWIC. 2009. COSEWIC Assessment and Addendum on the Black-footed Ferret Mustela nigripesin Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii pp.

Production note:

Please note this is an addendum to the existing 2000 COSEWIC Assessment and Status Report on the Black-footed Ferret Mustela nigripes in Canada.

COSEWIC would like to acknowledge Mark Brigham, Co-chair, Terrestrial Mammals Specialist Subcommittee, for preparing the addendum on the Black-footed Ferret (Mustela nigripes).

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3
Tel.: 819-953-3215
Fax: 819-994-3684


Également disponible en français sous le titre Évaluation et addenda du COSEPACsur le putois d’Amérique Mustela nigripes au Canada.

© Her Majesty the Queen in Right of Canada, 2009.
Catalogue No.CW69-14/583-2009E-PDF
ISBN: 987-1-100-13253-2

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COSEWIC Assessment Summary

Assessment Summary – April 2009

Common name: Black-footed Ferret
Scientific name: Mustela nigripes
Status: Extirpated
Reason for designation: Not observed in Canada since 1937. Considered extirpated following its assessment in 1974.
Occurrence: Alberta, Saskatchewan
Status history: Extirpated by 1974. Designated Extirpated in April 1978. Status re-examined and confirmed in May 2000 and in April 2009. Last assessment based on an existing status report with an addendum.

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COSEWIC Addendum

Addendum to the 2000 COSEWIC Assessment and Status Report on the Black-footed Ferret Mustela nigripes in Canada - 2009

Prepared by Mark Brigham, co-chair, Terrestrial Mammals Specialist Subcommittee

Black-footed Ferret (Mustela nigripes) Putois d'Amérique

Jurisdictions: Alberta, Saskatchewan, Parks Canada, CWS.

Current COSEWIC Status category:


Criteria applied:


Applicable current criteria:

Current report [indicate if not a living document]:

Current reason for designation:

Not caught in Canada since 1937. Considered extirpated in 1974.


Update to the status report not required (species’ status category remains unchanged)


sufficient information to conclude there has been no change in status category
not enough additional information available to enable a re-assessment

Evidence (indicate as applicable):

Wildlife species:

Change in eligibility, taxonomy or designatable units:yes no


Change in Extent of Occurrence (EO): yes no
Change in Area of Occupancy (AO): yes no
Change in number of known or inferred current locations:yes no
Significant new survey information: yes no

Population Information:

Change in number of mature individuals: yes no
Change in total population trend: yes no
Change in extent of population fragmentation: yes no
Significant new survey information: yes no


Change in nature and/or severity of threats: yes no


Change in effective protection: yes no

Rescue Effect:

Evidence of rescue effect: yes no

Quantitative Analysis:

Change in estimated probability of extirpation: yes no

Additional Considerations:

There has been no change in the status of this species since it was last assessed in 2000. The species has not been recorded in the wild, or as breeding in the wild, in Canada since 1937. It was first classified at extirpated in 1974. The species was erroneously suggested to have occurred in Manitoba in the COSEWIC database. There is no indication in the 1978 status report which was used in an unmodified form for the 2000 assessment for its occurrence in Manitoba. Likewise, in the 2008 draft recovery strategy (Tuckwell and Everest 2008) there is no indication that this species ever occurred in Manitoba.

A successful conservation breeding program has been providing black-footed ferrets for reintroduction in the U.S. and Mexico since 1991. The intent is to try to reintroduce the species to Grasslands National Park in Saskatchewan in 2009. There is currently a major captive breeding program which consists of one population (~ 5800 individuals have been born in captivity) held at seven different locations including the Toronto Zoo. Significant efforts are made to move individuals between locations to maintain genetic diversity within the captive population. Since 1992, the Toronto Zoo has raised 269 kits (young), the majority of which have been reintroduced into the wild in the U.S. and Mexico. It is likely that ferrets to be reintroduced to Grasslands National Park will come from this facility.


  • Pat Fargey (Grasslands National Park);
  • Jurisdictions of Alberta and Saskatchewan;
  • Parks Canada (Gilles Seutin, Patrick Nantel);
  • CWS(Theresa Fowler).

Sources of information:

2008 Draft Recovery plan for Black-Footed Ferrets. 1978 COSEWIC status report, which was used, unmodified, for the re-assessment in 2000.

Tuckwell, J., and T. Everest. 2008. Recovery Strategy for the Black-footed Ferret (Mustela nigripes) in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Parks Canada Agency. Ottawa. vii + 35 pp.

** NOTE: A copy of the 2000 COSEWIC Assessment and Status Report on the Black-footed Ferret is available on the Public Registry.

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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.


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 (2009)

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 Canada, provides full administrative and financial support to the COSEWIC Secretariat.