抄録
Five hundred and seventy-one stomachs of the red fox which had been collected in Nemuro and Kushiro Provinces, eastern Hokkaido during the winters of 1970-71, 1971-72, and 1972-73, were examined. The red-backed vole and fish were the two main foods of foxes in these areas. Livestock (carrion), birs, hares, and poultry were also important winter foods. Voles and hares were consumed most in late fall and early winter, while fish and livestock carries were taken most in late winter. Other food items eaten indicated no great monthly variation. There was a significant relationship between population indices of the red-backed vole in the study area and the percentage volume of voles in the fox diet during the three winters. When the population index of the vole in a low population year decreased to 1/5.7 of that in a high population year, the proportion of voles in the fox diet decreased only to 1/2.3. The decrease of voles in the fox diet in the low density year of the voles was compensated for by increased feeding on fish and wild birads. Coastal foxes fed mainly on fish, livestock, and wild birds, while inland foxes took mainly voles, hares, and poultry.
