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Since Gyrfalcons breed only in remote Arctic and subarctic habitats, this species is not covered by the Breeding Bird Survey. However, the Christmas Bird Count (CBC) does provide some coverage of the southern part of its wintering range. These results suggest wintering populations of the Gyrfalcon have shown moderate increases since about 1970. Directed surveys of nesting birds on the North Slope of the Yukon and in the mountains of south-western Yukon suggests breeding populations were stable between about 1977 and 2000, but have since been declining in abundance due to changes in population cycles of ptarmigans, their primary prey (Mossop 2011). Preliminary results from the Northwest Territories/Nunavut Bird Checklist Survey (B.T. Collins, Environment Canada, unpublished data) suggest little change in occurrence in survey areas between 1987 and 2007 (annual trend = -0.117, p<0.001).
Additional information on: Christmas Bird Count (CBC)
