How Conservation Status is Ranked in British Columbia
At the national level, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) is an independent body of experts who categorize species according to conservation risk. Species at risk are those that have been extirpated (meaning extinct in a local area, province, or country) or are designated as endangered, threatened, or of special concern.
Within British Columbia, ranking of the conservation status of species is based on a criteria developed by the international organization NatureServe. A species is also assigned subnational ranks, or “S-ranks” based on the status of species within each province or state in its range. The British Columbia Conservation Data Centre (CDC), in the Ministry of Environment, is the government body responsible for assigning the provincial S-ranks.
The CDC also publishes the provincial Red, Blue and Yellow lists of species that have been assessed by provincial biologists. Species legally designated as Extirpated, Endangered, or Threatened under the BC Wildlife Act are included on the provincial lists.
Terminology used by different conservation classification systems can be confusing. The following table shows equivalent designations for species considered “at risk” of extinction and those “not at risk” according to the classification systems referred to in the Environmental Trends reporting.
| Risk Level |
BC CDC S-ranks1 |
Provincial Lists2 |
COSEWIC Categories3 |
| At risk |
SX: Extinct/extirpated
SH: Historic
S1: Critically imperilled
S2: Imperilled |
Red List |
Extinct
Extirpated
Endangered
Threatened |
| S3: Special concern |
Blue List |
Special Concern |
| |
| Not at risk |
S4: Apparently secure
S5: Secure |
Yellow List |
Not at risk |
1 BC Conservation Data Centre Subnational ranks (S-ranks). S-ranks are based on many factors, including number and viability of existing occurrences, trends in population size and geographic distribution and threats facing the species or its habitat.
2 Provincial Lists: The BC CDC uses S-ranks to assign species to one of three provincial lists defined as:
- Red list: Extirpated or presumed extirpated (not reported for 20-40 years) species. Species legally designated as threatened or endangered under the provincial Wildlife Act and all candidates for such designation (the majority of red-listed species). Includes compound S-ranks: S1S2 and S1S3.
- Blue list: Species not immediately threatened but of concern because of characteristics that make them particularly sensitive to human activities or natural events. Includes compound S-ranks: S2S3 and S3S4 (animals only).
- Yellow list: all species not on the Red or Blue lists, but tracked by the CDC; they are not considered to be at risk.
3 Committee on the Status of Endangered Wildlife in Canada. Species assessed by COSEWIC are designated as:
- Extinct: no longer exists.
- Extirpated: no longer exists in the wild in Canada, but occurs elsewhere.
- Endangered: facing imminent extirpation or extinction.
- Threatened: expected to become endangered if limiting factors are not reversed.
- Special concern: may become threatened or endangered for a combination of reasons
- Not at Risk: evaluated and found to be not currently at risk of extinction
Species for which there is inadequate information to make an assessment are designated as ‘Data deficient’.
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