Red crossbill (Percna) COSEWIC assessment and status report: chapter 14

Technical Summary

Loxia curvirostra percna Bent 1912

Red Crossbill percna subspecies

Bec-croisé des sapins de la sous-espèce percna

Range of Occurrence in Canada: core, historic breeding range on insular Newfoundland, with occasional/suspected occurrences (and unknown breeding status) in Nova Scotia and Québec (Anticosti Island)


Extent and Area Information

Extent of occurrence (EO)(km2)
Encompasses the area of the core range of insular Newfoundland, and the area of other known or suspected locations of occurrences (Nova Scotia and Anticosti Island)
172 085 km2
Specify trend in EO Stable
Are there extreme fluctuations in EO? No
Area of occupancy (AO) (km2)
Forested area of insular Newfoundland, not including offshore islands
51 723 km2
Specify trend in AO Decline
Are there extreme fluctuations in AO? No
Number of known or inferred current locations Not applicable
Specify trend in # Not applicable
Are there extreme fluctuations in number of locations? Not applicable
Specify trend in area, extent or quality of habitat Decline in area, extent, and quality


Population Information

Generation time (average age of parents in the population) Approx. 2 years
Number of mature individuals 500 – 1 500
Total population trend: Decline
% decline over the last/next 10 years or 3 generations 75% decline based on Nfld. CBCs.
Are there extreme fluctuations in number of mature individuals? No
Is the total population severely fragmented? Not applicable
Specify trend in number of populations Not applicable
Are there extreme fluctuations in number of populations? Not applicable
List populations with number of mature individuals in each:


Threats (actual or imminent, to populations or habitats)

Habitat loss and degradation from forest harvesting
Conifer seed competition with and nest predation from red squirrels
Vehicle strikes


Rescue Effect (immigration from an outside source): No

Status of outside population(s)?
USA:
[other jurisdictions or agencies]
 
Is immigration known or possible?  
Would immigrants be adapted to survive in Canada?  
Is there sufficient habitat for immigrants in Canada?  
Is rescue from outside populations likely? No


Quantitative Analysis

Not applicable
 


Other Status


Status and Reasons for Designation

Status:
Endangered
Alpha–numeric code:
C1
Reasons for designation:
The percna subspecies of the red crossbill is considered a distinctive taxonomic group, with breeding likely restricted to the island of Newfoundland. Various population estimates suggest that it has declined markedly and steadily over the last 50 years, along with declines in the extent and quality of its habitat. A few records of the percna subspecies exist for Nova Scotia and other locations, but there is not enough information to determine its status there.


Applicability of Criteria

Criterion A (Declining Total Population):
The population has declined by over 50% in the last 10 years, so A2b may apply. However, this decline is based on the results of Christmas Bird Counts, which occur in a relatively small portion of the available habitat.
Criterion B (Small Distribution, and Decline or Fluctuation):
The EO and AO are both greater than 20 000 km2, so Criterion B does not apply.
Criterion C (Small Total Population Size and Decline):
Endangered (C1). The population is less than 2500 mature individuals (i.e. 500 - 1500), and a decline of at least 20% in 5 years is projected.
Criterion D (Very Small Population or Restricted Distribution):
Upper estimates suggest a population greater than 1000 mature individuals, so Criterion D does not apply.
Criterion E (Quantitative Analysis):
The information necessary to conduct a quantitative analysis is not available.

 

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