Ross’s gull (Rhodostethia rosea) COSEWIC assessment and status report: chapter 14
Rhodostethia rosea
Ross’s Gull
Mouette rosée
Range of Occurrence in Canada: Nunavut Territory and Manitoba
Extent and Area Information
Extent of occurrence (EO) (km2) Calculated by including areas of all breeding locations, including historical ones (e.g. Cheyne Islands) |
300 000 km2 |
Specify trend in EO | Unknown |
Are there extreme fluctuations in EO? | No |
Area of occupancy (AO) (km2) Calculated by selecting the four known breeding locations and using a 50 km radius around each location |
31 000 km2 |
Specify trend in AO | Unknown |
Are there extreme fluctuations in AO? | No |
Number of known or inferred current locations | 3 known in 2005/06: Churchill, Penny Strait, Cheyne Islands |
Specify trend in # | Unknown |
Are there extreme fluctuations in number of locations? | No |
Specify trend in area, extent or quality of habitat | Stable |
Population Information
Generation time (average age of parents in the population) |
>10 years |
Number of mature individuals | Up to 20 observed, likely more |
Total population trend | Unknown, but likely stable |
% decline over the last/next 10 years or 3 generations | Unknown |
Are there extreme fluctuations in number of mature individuals? | No |
Is the total population severely fragmented? | Based on known groups, yes |
Specify trend in number of populations | Stable |
Are there extreme fluctuations in number of populations? | No |
List populations with number of mature individuals in each: 1. Churchill – 4 (2005); 2: Penny Strait – 10 (2005); 3: Cheyne Islands – 6 (2006); 4: Prince Charles Island - ? |
Threats (actual or imminent threats to populations or habitats)
Industrial development
Human disturbance
Climate change
Human disturbance
Climate change
Rescue Effect (immigration from an outside source)
Status of outside population(s)? Major breeding population in Siberia; unknown trend, but possibly stable |
|
Is immigration known or possible? | Yes |
Would immigrants be adapted to survive in Canada? | Yes |
Is there sufficient habitat for immigrants in Canada? | Yes |
Is rescue from outside populations likely? | Yes |
Quantitative Analysis
N.A.
Current Status
COSEWIC: Threatened (2001, 2007)
Status and Reason for Designation
Status: Threatened |
Alpha-numeric code: Met criterion for Endangered, D1, but designated Threatened, D1, because there is potential for rescue and because more birds likely occur in unsurveyed areas. |
Reason for designation: In Canada, this species is known to occur in small numbers in very few locations. Threats include disturbance in some breeding areas and changes in ice and snow patterns associated with climate change. |
Applicability of Criteria
Criterion A (Declining Total Population):
Does not meet criterion.
Does not meet criterion.
Criterion B (Small Distribution, and Decline or Fluctuation):
Does not meet criterion.
Does not meet criterion.
Criterion C (Small Total Population Size and Decline):
Does not meet criterion.
Does not meet criterion.
Criterion D (Very Small Population or Restricted Distribution):
Meets D1 Endangered because known population < 250 mature individuals.
Meets D1 Endangered because known population < 250 mature individuals.
Criterion E (Quantitative Analysis):
No quantitative analyses.
No quantitative analyses.
Page details
- Date modified: