Foods of arctic foxes (Alopex lagopus) during winter and spring in westernAlaska

During 1986-1991, carcasses of 619 arctic fares (Alopex lagopus) collected from local trappers and at biological field camps on the Yukon-Kuskokwim De lta in western Alaska from November through May were analyzed to determine gastrointestinal contents, age, sex, and body condition. Prey in declining order of importance were small mammals (95% tundra voles, Microtus oeconomu s), birds, marine mammals, and fishes. Foxes with small mammal remains in t heir stomachs were captured farther from the Bering Sea coast ((X) over bar = 5.2 km) than those without small-mammal remains (2.8 km); foxes consumin g remains of marine mammals were closer to the coast (1.9 km) than others ( 4.9 km). Although eggshells had a poor likelihood of occurrence in stomachs , they were found in all months and years. In 1986 and 1987, foxes consumed fewer small mammals than in other years. Mean ages of foxes captured in 19 86 (3.7 years) and 1987 (3.2) were greater than in all ether years (1.5). C apture of adults was more common as winter progressed. Indexes of subcutane ous fat decreased annually in April-May and were highest in 1991, when occu rrence of carrion of marine mammals was highest.