Prioritization Criteria developed by COSEWIC for ranking wildlife species
Updated November 2011
i. Taxonomic level
Give greater priority to full species, then subspecies, then below species level Designatable Units
ii. Portion of Global Range in Canada
Endemic to Canada or very small global range
> 50 percent of extant global range or population in Canada
< 50 percent of extant global range or population in Canada
* Must take into account the wildlife species' life history and which part of its range (this may include non-breeding range) represents the greatest conservation concern.
iii. Existing global conservation status
IUCN red list or NatureServe G-rank is G1 or G#T1
NatureServe G-rank is G2, G3, G#T2, or G#T3
* Where an IUCN or NatureServe status rank does not exist, provide information from other systems or otherwise useful to assess global status. If existing status ranks are deemed incorrect or out of date, the SSC should provide a comment.
iv. Canadian population size and trends
Very small population size
* According to a measure that is appropriate for the taxa as explained by the SSC in the documentation
Severe decline (>70%)
Decline (>50% but < 70%)
Suspected decline or less than 50% decline
* Decline over 3 generations or 10 years, whatever is longer, in population number or inferred by decline in habitat or # of locations.
Threats, either ongoing or likely to occur, that are likely to affect a large percentage (>50%) of population
Threats with observed impact, but less than above
vi. Small extent of occurrence or (index of) area of occupancy
Identified threat and very small extent of occurrence or (index of) area of occupancy, or all individuals in 5 or fewer subpopulations.
Limiting Biological Factors
Other biological considerations (e.g., age to maturity, etc.)