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

Caveats and limitations

Knowledge of which wildlife species may be at risk is far from complete, and only a portion of those suspected to be at risk can be assessed. The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) prioritizes assessments based on expert opinion. Early efforts focused mainly on vertebrates and plants, and these are also the best-known wildlife species. As a result, these wildlife species are over-represented among wildlife species that have been reassessed. Similarly, knowledge of wildlife species is greatest in southern Canada and in terrestrial systems.

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.