Starting about 1836 and continuing into the 1930's fur traders and fox farmers introduced arctic fox (Alopex lagopus) to several islands in the Aleutian Chain--islands that were previously free of terrestrial mammalian predators (Jones and Byrd 1979). By 1937, this exotic furbearer was successfully introduced on almost all of the Aleutian Islands. Their effect on native avifauna was immediate and acute since they depended on natural foods, including indigenous birds for sustenance and it soon became a pest of significant importance in the Aleutian Islands. Aleutian Canada geese (Branta canadensis leucopareia) were a major prey species, and by 1967 were listed as endangered. Recovery plans for the Aleutian Canada goose specified the sequential eradication of arctic fox throughout the Aleutian Islands including Kiska Island, a large land mass (28,200 ha) and historic breeding site of this species in the western Aleutians. The investigations of the efficacy of the pesticide sodium fluoroacetate (1080) against arctic fox and the potential hazards