Summer food habits of sympatric Arctic Foxes, Alopex lagopus, and Red Foxes, Vulpes vulpes, in the northern Yukon Territory

Abstract

Food habits of sympatric Arctic Foxes (A/apex lagopus) and Red Foxes ( Vulpes vulpes) were determined from 31 Arctic Fox sca ts (from three active natal dens) and 39 Red Fox scats (from two active natal den s) collected in the nort hern Yukon Territory in summer 1985. Prey consumption was quantified in terms of percentages of fragments and percent frequency occurrence of taxa. Microt inae, primarily the Varying Lemming (Dicrosionyx groenlandicus) was the major prey for both fox species. The Brown Lemming (Lemmus sibiricus) and Tundra Vole (Micro/us oeconomus) [Red Fox only], and Northern Bog Lemming (Synaplomys borealis) [Arctic Fox o nly] were consumed in lower quantities. Several bird species were consumed, primarily by Red Fo xes. D. groenlandicus was consumed less frequently and bird s more frequently by Red Foxes on the mainland (Yukon Coasta l Plain) tha n by those on Hersche l Island. The diets of sympatric Arctic Foxes and Red Foxes were similar; however, the Red Fox used more bird s and less D. groenlandicus than did the Arctic Fox.