Autumn and winter distributions of lesser snow geese from the Western Canadian Arctic and Wrangel Island, Russia, 1953-1992

Recent and historical changes in the autumn and winter distributions of lesser snow geese Anser caerulescens caerulescens that breed in the Western Canadian Arctic and on Wrangel Island were evaluated from legband recoveries from hunter-killed geese and from resightings of neckbanded geese, using data from banding in the Western Arctic in 1953-1966, 1973-1976, and 1987-1989 and on Wrangel Island in 1961-1963, 1975-1979, and 1988-1989. There has been a gradual eastward shift in the location of the autumn staging area in the Canadian prairies used by snow geese from the Western Arctic. In the 1950s and 1960s, 74% of the legband recoveries in the Canadian prairies occurred in Alberta, and 26% were in Saskatchewan. By the late 1980s and early 1990s, only 36% of the legband recoveries and 32% of the neckband obervations were in Alberta, and the remainder were in Saskatchewan. A small proportion of the Wrangel Island population moved through the Canadian prairies in autumn; most of the population apparently migrated along the Pacific coast. There was no evidence of broad-scale changes in the fall distribution of Wrangel Island geese using the Pacific route. Nine major areas where geese from one or both populations spent the winter were identified. In the 1960s and 1970s, 90% of the Western Arctic geese wintered in California, and about 8% wintered in the Western Central Flyway. By the late 1980s, the Western Central Flyway component had increased to 24% of the total population, whereas the California component had declined to 76%. In the 1960s and 1970s, approximately 90% of the Wrangel Island population wintered in California and 10% in the Fraser-Skagit region. Obervations of neckbanded geese in the late 1980s and early 1990s indicated that only 47% moved south to California while at least 52% of the population wintered in the Fraser-Skagit region. Possible explanations of the changes in winter distribution of Wrangel Island and Western Arctic snow geese, including geomorphic differences in survival, productivity, and movement patterns, are discussed.