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Data Sources and Methods for the Changes in Wildlife Species Disappearance Risks Indicator


COSEWIC status assessments

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) uses a process based on science and on Aboriginal and community knowledge to assess wildlife species at risk.Footnote [1] All native mammals, birds, reptiles, amphibians, fish, arthropods, mollusks, vascular plants, mosses and lichens are included in COSEWIC's current mandate.

In doing its work, COSEWIC develops the prioritized "COSEWIC Candidate List" of wildlife species needing assessment, manages the production of wildlife species status reports, and holds meetings at which wildlife species are assessed and assigned to risk categories. In all of its actions, COSEWIC uses the best available information relevant to assessing a wildlife species' risk of extinction or extirpation, which it may obtain from any credible source of knowledge of the wildlife species and its habitat.

COSEWIC annually commissions status reports for high-priority candidate wildlife species on the COSEWIC Candidate List or for wildlife species that require reassessment ("update status reports"). A status report is a comprehensive technical document that compiles and analyzes the best available information on a wildlife species' status in Canada. It contains information on the basic biology of a wildlife species, as well as information on a wildlife species' distribution in Canada, population sizes and trends, habitat availability and trends, and threats to the wildlife species.

All status reports (including updated status reports and unsolicited reports) must meet COSEWIC's standards for quality and completeness, and are subject to thorough reviews by the appropriate Species Specialist Subcommittee and the Aboriginal Traditional Knowledge Subcommittee, as well as by jurisdictions that have a responsibility for the wildlife species (including governments of the provinces and territories where the wildlife species occurs, federal departments responsible for the wildlife species, and wildlife management boards). Additional outside experts may also be asked to review status reports. When the reviews are complete and any required revisions have been incorporated, the report is distributed to all COSEWIC members.

COSEWIC members use status reports as a basis for discussion and for status assignment at semi-annual Wildlife Species Assessment Meetings. For each wildlife species considered at a Wildlife Species Assessment Meeting, COSEWIC sequentially considers each of five items to determine a Canadian status designation:

  1. Is there sufficient information presented in the report to determine wildlife species eligibility?
  2. Given sufficient information, is the wildlife species eligible for assessment?
  3. Is the status report adequate and acceptable for assessment purposes?
  4. What status is suggested by application of approved COSEWIC quantitative assessment criteria and guidelines?
  5. Does the suggested status conform to the COSEWIC definition for the proposed status category?

Wildlife species are assigned to one of seven status categories: Extinct (X), Extirpated (XT), Endangered (E), Threatened (T), Special Concern (SC), Not at Risk (NAR) or Data Deficient (DD). In 2012, 911 wildlife species had status categories (see Table 1).

Table 1: Status of wildlife species assessed by COSEWIC as of December 2012
StatusTotal number of species
Special Concern*190
Not at Risk172
Data Deficient56
Grand Total911

* The sum of species designated as Endangered, Threatened and of Special Concern make up a total of 646 species at risk.Footnote [2]

Download data file (Excel/CSV; 630 B)

Status changes

COSEWIC also notes a "change status" in its assessments, based on the most recent two assessments. This change status provides the base information for the CESIindicator, as summarized in Table 2.

Species with a change status of "New" have only been assessed once; they are therefore not included in the indicator. Species with a status of "Data Deficient" on one or both assessment dates are also excluded.

Wildlife species that are reported in the "Reassigned" category are individually examined, and grouped into CESI units that can be considered as a whole. If the direction of change can be determined unambiguously, the units are assigned to the appropriate CESIchange group. For example, a wildlife species that was split into two subspecies on reassessment would be treated as one CESI unit. If both new subspecies changed in the same direction on reassessment, the unit would be given a CESI change category.

For 2012 data, the 71 wildlife species with a status change of "Reassigned" were grouped into 36 CESI units whose status could be examined. Of the 36 units, 8 were assigned to the no change category, 3 to lower risk and 3 to higher risk, while the remaining 22 could not be determined. For detailed information on the allocation of wildlife species with a COSEWIC change status of "Reassigned," please consult Annex 1.

Table 2: Relationship between COSEWIC status changes and CESI changes in disappearance risk
COSEWICchange statusDefinitionCESI changes in disappearance risk
In a higher risk categoryWildlife species placed in a higher risk category after the most recent reassessmentHigher risk
No change1Wildlife species stays in the same category after reassessmentNo change
In a lower risk categoryWildlife species placed in a lower risk category after reassessmentLower risk
No longer at riskWildlife species moved to the Not at Risk category from a risk categoryLower risk
NewWildlife species examined for the first time are assigned a category of NewExcluded
ChangedWildlife species moved to the Data Deficient category from a risk category or to a risk category from the Data Deficient categoryExcluded
Reassigned2Wildlife species that has been assigned to a different designatable unit than previouslyCase-by-case assignment

1 Wildlife species that are "data deficient" on both dates when an assessment is made are excluded.
2 Wildlife species that are reported in the “Reassigned” category are examined individually, and grouped into related units. Where the direction of change can be unambiguously determined, these units are assigned to the appropriate change category.


Footnote 1

Many wildlife species in Canada have not yet been assessed by COSEWIC, but are suspected of being at some risk of extinction or extirpation. These wildlife species, referred to as “candidate wildlife species”, are identified and prioritized by the Species Specialist Subcommittees or by the Aboriginal Traditional Knowledge Subcommittee as candidates for detailed status assessment. Candidates may also include wildlife species already assessed by COSEWIC as Not at Risk or Data Deficient, but where new information suggests they may be at risk.

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Footnote 2

COSEWIC includes the “Extirpated” category in the at-risk group in their reporting.

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