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

4. Methods

4.1 Committee on the Status of Endangered Wildlife in Canada 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. All native mammals, birds, reptiles, amphibians, fish, arthropods, molluscs, 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. The reports 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 one of seven status categories: Extinct (X), Extirpated (XT), Endangered (E), Threatened (T), Special Concern (SC), Not at Risk (NAR) or Data Deficient (DD). As of May 2015, 952 wildlife species had status categories (see Table 1).

Table 1: Status of wildlife species assessed by COSEWIC as of May 2015
StatusTotal number of species
EndangeredFootnote [A]316
ThreatenedFootnote [A]167
Special ConcernFootnote [A]205
Not at Risk172
Data Deficient54

Download data file (Excel/CSV; 639 B)

4.2 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 Canadian Environmental Sustainability Indicators (CESI) indicator, 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 CESI change 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. If the direction of change cannot be determined, the unit is given a CESI change category of "Unknown."

For the 2015 data, 79 wildlife species with a status change of "Reassigned" were grouped into 40 CESI units whose status could be examined. Of the 40 units, seven were assigned to the "No change" category, three to "Lower risk" and three to "Higher risk," while the remaining 27 could not be determined. Units that cannot be unambiguously assigned to a change category are not included in the indicator. For detailed information on the allocation of wildlife species with a COSEWIC change status of "Reassigned," consult Annex 1.

Table 2: Relationship between COSEWIC status changes and CESI changes in disappearance risk
COSEWIC status changeDefinitionCESI changes in disappearance risk
In a higher risk categoryWildlife species placed in a higher risk category after the most recent reassessmentHigher risk
No changeFootnote [A]Wildlife 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
ReassignedFootnote [B]Wildlife species that has been assigned to a different designatable unit than previouslyCase-by-case assignment
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