Data Sources and Methods for the Changes in Wildlife Species Disappearance Risks Indicator
- 1. Introduction
- 2. Description and rationale of the Changes in Wildlife Species Disappearance Risks indicator
- 3. Data
- 4. Methods
- 5. Caveats and limitations
- 6. References and further reading
- Annex 1: Allocation of wildlife species assigned with a change status of Reassigned by the Committee on the Status of Endangered Wildlife in Canada, 2016
5. 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 (the Committee) 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.
Species that are at risk can take a long time to recover, especially if they are long-lived and slow to reproduce. Also, improvements to habitat, for example, can take many decades. Under the Species at Risk Act, the Committee is required to reassess wildlife species previously designated in a category of risk with an update status report every 10 years or earlier.Footnote 
Many wildlife species in Canada have not yet been assessed by the Committee, 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 the Committee as Not at risk or Data deficient, but where new information suggests they may be at risk.
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