COSEWIC wildlife species assessment: candidate wildlife species

Priority setting for new wildlife species to be assessed

The Species at Risk Act (SARA) has a number of goals that can be interpreted to provide direction to the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in setting priority for species to be assessed. Section 6 of SARA says

"The purposes of this Act are to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened."

Note that the preamble to the act says "all Canadians have a role to play in the conservation of wildlife in this country, including the prevention of wildlife species from becoming extirpated or extinct" as well as "the Government of Canada is committed to conserving biological diversity".

SARA section 15(1)(b): [The functions of COSEWIC are]:

"determine when wildlife species are to be assessed, with priority given to those more likely to become extinct."

The priority setting scheme was extensively changed from 2012-2015 to increase the transparency and repeatability of the process used by COSEWIC to determine which species are chosen for detailed assessment.

In this process COSEWIC identifies species to be assessed almost 2 years ahead of time. This advance warning is to facilitate the process of acquiring data and recruiting status report writers by:

  • alerting scientists, naturalists, stakeholders and managers as to which wildlife species are about to be assessed
  • influencing funding priorities for inventories and threats assessment
  • giving warning to potential bidders to start thinking about submitting proposals for contracts at the time Calls for Bids are posted; and
  • encouraging the acquisition, compilation, synthesis and analysis of data on the wildlife species that will facilitate the development of a status report.

COSEWIC’s priority setting takes into account the following additional guidelines:

  • When all else is equal, species are given a higher priority than subspecies, or other Designatable Units (DU) below the species level.
  • When all else is equal, wildlife species that have a significant portion of their range or of their numbers in Canada will be given higher priority than those that have a very small proportion of their range or numbers in Canada.
  • When all else is equal, wildlife species with a highly restricted global range or wildlife species with disjunct unique populations in Canada will be given higher priority.
  • When all else is equal, species with less secure global status will be given higher priority.
  • When all else is equal, species with global ranges contracting towards Canada will be given higher priority.
  • When all else is equal, species represented in Canada by a disjunct population(s) will be given a higher priority.
  • Wildlife species considered to be susceptible or impacted by greater or more imminent threats will be given higher priority. Similarly, wildlife species that have undergone greater declines (if known) over 3 generations or 10 years will be given higher priority.

Candidate wildlife species are those not yet assessed by COSEWIC or those that have been previously assessed but are now suspected to be at a higher level of risk of extinction or extirpation from Canada.

In order to compile the COSEWIC Candidate List, SSCs and the ATK committee select high priority wildlife species from their respective candidate lists. The methodology used to develop and prioritize species on Species Specialist Subcommittees (SSC) and Aboriginal Traditional Knowledge Subcommittee (ATK SC) candidate lists may vary because of differences in life histories and information available but should be based on these general priority setting guidelines. For each wildlife species, the committees submit a supporting rationale on the prioritization criteria template (available upon request).

The chair can direct an ad hoc committee to draft rationales for species not covered by existing SSCs and any member of COSEWIC may bring forth a species not covered by an SSC. The draft rationales should be circulated to COSEWIC by the Secretariat for a review period of 1 month. Members can comment to the SSC by email on the rationales. After incorporating suggestions the SSC and ATK committees forward to the Secretariat the final candidate rationales. The Secretariat, working with members of the Priority for New Species Working Group, will generate ranking scores using the following process:

Step 1. The Priority Setting Working Group generates a range of probable International Union for Conservation of Nature (IUCN) scores for the proposed candidate species that incorporates the range of uncertainty in the preliminary information. These ranges of possible outcomes are assigned scores as per Figure 1.

Figure 1. Scores assigned to preliminary IUCN assessments
Critically Endangered Endangered Vulnerable
(= COSEWIC Threatened)
Least Concern / Data Deficient
1 - - -
2 - -
3 -
4 -
- 3 - -
- 4 -
- 5
- - 5 -
- - 6
- - - 7

Step 2. Based on information in the final candidate rationales, Canadian Responsibility scores (Table 1) are assigned and Global (G) ranks are consulted. Using Table 2 that combines the Canadian Responsibility Score and G or IUCN ranks (vertical) along with the IUCN score (horizontal), a raw bin number is assigned. Choose the Responsibility Score or G/IUCN rank that gives the higher priority (the lower the raw bin number, the higher the priority).

Table 1. Responsibility class
Responsibility Class Proportion of the Population in Canada
1 Endemic (species, subspecies or DU):100% of the range, area or population within Canada
2 Very high: 75 to 99% responsibility
3 High: 51-74 % responsibility
4 Moderately High: 30 to 50% responsibility
5 Intermediate: 11-29% responsibility
6 Low and widespread: < 10% global responsibility but occurs over >30% of Canada
7 Low and localized

Table 2. Determining preliminary priority bin scores
  Priority Assigned to IUCN Score
Canadian Responsibility Score/G/IUCN rank1
1 or G1 or IUCN CE or E  1 2 3 4 5 6 13
2 or G1G2 2 3 4 5 6 7 14
3 or G2 or IUCN V 3 4 5 6 7 8 15
4 or G2G3 4 5 6 7 8 9 16
5 or G3 5 6 7 8 9 10 17 
6 or G3G4 6 7 8 9 10 11 18 
7 or G4G5 or G5 7 8 9 10 11 12 19

Step 3. Priority Bin Scores are adjusted using the following rules:

  1. species with ranges collapsing towards Canada move up one priority bin.
  2. species represented in Canada by only a disjunct population(s) move up one priority bin.
  3. subspecies, varieties or DUs below the species level move down one priority bin score.

Step 4. Priority bin scores are circulated to COSEWIC at least 4 weeks prior to the April Wildlife Species Assessment Meeting and then COSEWIC reviews and discusses the binned list at that meeting. Priority can be adjusted based on this discussion which can include considerations of SSC and ATK workload, costs, availability and timing of new information, and efficiencies from grouping species together (bundling). COSEWIC then selects the top priority Wildlife Species for status report commissioning in the fall Call for Bids a year and a half later. This results in the COSEWIC Candidate List.

The final rationales for COSEWIC Candidate wildlife species are This email address is being protected from spambots. You need JavaScript enabled to view it..

Note: Wildlife species that are to be assessed as subspecies or putative DUs or as part of ecosystem bundles should be treated as separate species in this process. If there is potentially more than one DU, data should be provided for those putative DUs that are thought to be at risk.


(1) whichever results in higher priority

About us

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is an independent advisory panel to the Minister of Environment and Climate Change Canada that meets twice a year to assess the status of wildlife species at risk of extinction. Members are wildlife biology experts from academia, government, non-governmental organizations and the private sector responsible for designating wildlife species in danger of disappearing from Canada.


COSEWIC secretariat
Canadian Wildlife Service
Environment and Climate Change Canada
351 St. Joseph Blvd, 16th floor
Gatineau QC K1A 0H3

Telephone: 819-938-4125
Fax: 819-938-3984
Email: ec.cosepac-cosewic.ec@canada.ca

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