ARCTIC Natural History of the Peregrine Falcon in the Keewatin District of the Northwest Territories

• Main Authors: Gordon S Court, C. Cormack Gates, David A. Boag
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1987
• Subjects: Arctic; Canada; Greenland; Hudson; Hudson Bay; Northwest Territories; Falco peregrinus; Keewatin; peregrine falcon; Tundra; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.511.4981; http://pubs.aina.ucalgary.ca/arctic/Arctic41-1-17.pdf

ABSTRACT. A dense, productive population of peregrine falcons (Falcoperegrinus) was studied for five years on a 450 k m 2 study area located along the northwest coast of Hudson Bay. The mean internest distance of 3.3 km represents the highest nesting density on record for the species in the Arctic. Morphometric and plumage characteristics of adults in the population suggest they are intermediate between Ep. tundrius from farther north and Ep. anatum from boreal regions to the south and west. The migratory pathway used by this population of birds is similar to that used by peregrines from Alaska, northern Canada, and Greenland. Both timing of arrival on the breeding grounds and clutch initiation are influenced strongly by spring weather patterns. Nineteen species of birds and three species of mammals were used as prey; however, in most years the bulk of the diet consisted of six species of birds and one mammal. A dramatic increase in the density of territorial peregrines in a year of high microtine rodent abundance, coupled with changes in various measùres of reproductive performance, suggested that use of lemmings by falcons can be significant in some years. Suggestions that peregrines lay fewer eggs in the arctic part of their range were not supported. Broods hatched asynchronously, with the last-hatched young dying in about one-half of all broods of our. Surviving last-hatched young in broods of four grew at rates similar to older nest mates. Brood size was high as that for any tundra nesting peregrine population on record. Key words: peregrine falcon, Falco peregrinus tundrius, morphology, migration, fwd, growth, productivity RÉSUMÉ. On a étudié pendant cinq ans une population dense et productive de faucons pèlerins (Falcoperegrinus) dans un territoire de 450 km ’ situ6 le long de la côte nord-ouest de la baie d’Hudson. La distance moyenne de 3,3 km entre les nids repksente la plus haute densité de nidification relevee dans