Northern spotted owl (Strix occidentalis caurina) recovery strategy: chapter 26

Appendix 4

COSEWIC Criteria for Endangered and Threatened Species

COSEWIC Organization and Procedures Manual

Table 2: COSEWIC Criteria for Endangered and Threatened Species
These are essentially IUCN Red List criteria (IUCN 1994) that were reviewed and evaluated by COSEWIC (COSEWIC 1999). See IUCN Red List Categories (IUCN 1994) for definitions and interpretation guidelines.
	Endangered	Threatened
A. Declining Total Population
Population decline rate of at least:	50% in 10 years or 3 generations	20% in 10 years or 3 generations
using either (1) population reduction observed, estimated, inferred‚ or suspected in the past or (2) population decline projected or suspected in the future. based on a) direct observation b) an index of abundance appropriate for the taxon c) a decline in area of occupancy, extent of occurrence and/or quality of habitat d) actual or potential levels of exploitation e) the effects of introduced taxa, hybridisation, pathogens, pollutants, competitors or parasites
B. Small Distribution and Decline or Fluctuation
Either extent of occurrence or area of occupancy and any 2 of the following 3:	<5,000 km² <500 km²	<20‚000 km² <2‚000 km²
(1) either severely fragmented:	(isolated populations with a reduced probability of recolonization, once extinct)
orknown to exist at # locations	≤5	≤10
(2) continuing decline in any of the following: a) extent of occurrence b) area of occupancy c) area, extent and/or quality of habitat d) number of locations or populations e) number of mature individuals (3) fluctuating in any of the following: a) extent of occurrence b) area of occupancy c) number of locations or populations d) number of mature individuals	any rate >1 order/mag	any rate >1 order/mag
C. Small Total Population Size and Decline
Number of mature individuals and 1 of the following 2: (1) rapid decline rate of at least (2) continuing decline and either (a) fragmentation or (b) all individuals in a single population	<2‚500 20% in 5 years or 2 generations any rate all populations <250	<10,000 10% in 10 years or 3 generations any rate all populations <1‚000
D. Very Small or Restricted
Either (1) # of mature individuals or (2) population is susceptible	<250 (not applicable)	<1,000 area of occupancy <100 km² or # of locations <5
E. Quantitative Analysis
Indicating the probability of extinction in the wild to be at least:	20% in 20 years or 5 generations	10% in 100 years
Special Concern: Species which are particularly sensitive to human activities or natural events but are not endangered or threatened species.
Examples of reasons why a species may qualify for “Special Concern”: A species that is particularly susceptible to a catastrophic event (e.g., a large seabird population near oil tanker route) A conservation-dependent species that would likely become at risk if not for active protection and management (e.g., a fish or mammal species protected from over-harvest) A recovering species, no longer qualifying for risk categories but not yet clearly secure, or subject to resumption of threat in future
Examples of reasons why a species may not qualify for “Special Concern”: Rarity alone in the absence of recognized threat Threat with little possibility of serious harm (e.g., large, fecund population subject to harvest)

Page details

Date modified:: 2010-02-19