Burrowing owl (Athene cunicularia) COSEWIC assessment and status report: chapter 13
Technical Summary
Athene cunicularia
Burrowing Owl
Chevêche des terriers
Range of Occurrence in Canada: AB, BC, SK, MB (essentially extirpated in BC and MB)
Extent and Area Information
| Extent of occurrence (EO) (km2) | ca. 160 000 km2 |
| specify trend (decline, stable, increasing, unknown) | Decline |
| are there extreme fluctuations in EO (> 1 order of magnitude)? | No |
| area of occupancy (AO) (km2) | ca. 5 000 to 10 000 km2 |
| specify trend (decline, stable, increasing, unknown) | Decline |
| are there extreme fluctuations in AO (> 1 order magnitude)? | No |
| number of extant locations | Not applicable |
| specify trend in # locations (decline, stable, increasing, unknown) | |
| are there extreme fluctuations in # locations (>1 order of magnitude)? | |
| habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat | Declining |
Population Information
| generation time (average age of parents in the population) (indicate years, months, days, etc.) | 2-3 years |
| number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values) | ca. 800-1600 |
| total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals | Declining |
| if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period) combined data from Alberta, Saskatchewan and Manitoba. |
ca. 90% through 1990s; ca. 57% 1994-2004 |
| are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)? | No |
| is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant / year)? | No |
| list each population and the number of mature individuals in each | |
| specify trend in number of populations (decline, stable, increasing, unknown) | |
| are there extreme fluctuations in number of populations (>1 order of magnitude)? |
Threats (actual or imminent threats to populations or habitats) [add rows as needed]
- Loss, fragmentation, and degradation of breeding, migration and wintering habitat
- Reduced immigration from neighbouring U.S. populations
- Increased predation on adults and young
- Poor reproductive success in most years, preceding population decreases in the next year
- Reduced immigration from neighbouring U.S. populations
- Increased predation on adults and young
- Poor reproductive success in most years, preceding population decreases in the next year
Rescue Effect (immigration from an outside source): Very low; habitat loss is major source of decline
| does species exist elsewhere (in Canada or outside)? | Yes |
| status of the outside population(s)? | Declining |
| is immigration known or possible? | Yes |
| would immigrants be adapted to survive here? | Yes |
| is there sufficient habitat for immigrants here? | Declining |
Quantitative Analysis
Current Status
COSEWIC: Endangered (2001, 2006)
Status and Reasons for Designation
| Status: Endangered |
Alpha-numeric code: A2bc; C1 |
| Reasons for Designation: This grassland owl has suffered significant declines across its North America range; Canadian populations declined 90% in the 1990s and the species is essentially extirpated from British Columbia and Manitoba. This population decline slowed somewhat between 1994 and 2004, but remained at approximately 57%. The true cause or causes of this widespread decline remain unknown. |
|
Applicability of Criteria
Criterion A (Declining Total Population):
Endangered A2bc; population has declined by about 57% in last three generations.
Endangered A2bc; population has declined by about 57% in last three generations.
Criterion B (Small Distribution, and Decline or Fluctuation):
population not fragmented or fluctuating
population not fragmented or fluctuating
Criterion C (Small Total Population Size and Decline):
Met Endangered C1; population less than 2000 and decline likely to continue.
Met Endangered C1; population less than 2000 and decline likely to continue.
Criterion D (Very Small Population or Restricted Distribution):
Not applicable; population and AO/EO too large
Not applicable; population and AO/EO too large
Criterion E (Quantitative Analysis):
Not done.
Not done.