Latitudinal Differences in the Breeding and Molt Schedules of Alaskan Red-Backed Sandpipers (Calidris alpina)
Holmes RT. 1971. Latitudinal Differences in the Breeding and Molt Schedules of Alaskan Red-Backed Sandpipers (Calidris alpina). The Condor. 73(1):93-99
On the Yukon-Kuskokwim Delta in western Alaska, adult C. alpina arrive in mid-May, establish territories, pair, nest, and care for young before starting their prebasic molt. After the young fledge, the red-backs shift from inland marsh tundra to coastal habitats, at which time molt intensifies. Feather replacement is complete prior to arrival in late September and October on their north temperature wintering quarters. The result is that breeding and molt are fitted, in sequence, into the summer schedule of events and do not overlap. In the C. alpina populations at Barrow, Alaska, 10° latitude farther north, breeding and molt overlap and molt proceeds at a faster rate. Such modifications are results of adaptive responses to the shorter summers at the higher latitudes and, to a lesser extent, to the more severe and unpredictable weather there. Results support the hypothesis that the timing of breeding season events in arctic shorebird populations is strongly affected by the length and character of the summer season.
- Type
- Journal Article
- Authors
- Holmes, Richard
- Units
- ARCN , BELA , CAKR
- Keywords
- Arctic, Barrow, Birds, Breeding Biology, dunlin, Molting, Population Ecology, Shorebirds, Subarctic, Yukon-Kuskokwim Delta