ARCTIC Natural History of the Gyrfalcon in the Central Canadian Arctic

• Main Authors: K. G. Poole, R. G. Bromley
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1987
• Subjects: Key words; gyrfalcon (Falco rusticolus; natural history; reproductive ecology; central Arctic; Arctic; Falco rusticolus; gyrfalcon
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.493.4612; http://pubs.aina.ucalgary.ca/arctic/Arctic41-1-31.pdf

Each year 14-18 territories were occupied. The mean intemest distance was 10.6 k m, giving one of the highest recorded densities for the species. There was a tendency for regularity in spacing of territories. Most (85%) nests were in abandoned stick nests of common ravens or golden eagles. Rough-legged hawk nests were not used by gyrfalcons, despite numerous available. Mean date of i itiation of laying was 8 May. Mean size of clutch was 3.80 and of brood was 2.53, and mean productivity was 1 S O fledged young. A reduction of 48 % from estimated number of eggs laid to number of fledglings was determined. Reproductive success declined with increased severity of spring weather, notably increased days and amount of precipitation.