Den Use by Arctic Foxes in Northern Alaska

Abstract

Den use by arctic foxes (Alopex lagopus) was examined near the Prudhoe Bay oil field and on a nearby undisturbed area on the Colville River Delta in northern Alaska. The density of dens at Prudhoe Bay (1 den/12 km²) was approximately three times that on Colville Delta (1 den/34 km²). Thirty-three percent of the Prudhoe Bay dens appeared to be of recent origin compared to 11% on the Colville Delta. Survival or production of juvenile foxes decreased on both study areas in 1977 when densities of lemmings (Dicrostonyx torquatus and Lemmus sibiricus) were low, but the decrease was less pronounced at Prudhoe Bay. Foxes that raised young at Prudhoe Bay in 1977 were those living near petroleum development facilities. The utilization of garbage by Prudhoe Bay foxes probably accounted for many of the observed differences between study sites. Common features of spring and summer den use by arctic foxes included a selection of historically preferred den sites, splitting litters into multiple dens, and the fidelity of some adult and juvenile foxes to dens in successive years. Winter use of dens was common at Prudhoe Bay.