DIET OF ARCTIC FOXES (ALOPEX-LAGOPUS) IN ICELAND

Arctic foxes, Alopex lagopus, live in low productivity arctic and nort hern tundra habitats, where they generally prey heavily on lemmings. I n Iceland, however, no lemmings are present, and the Foxes have a very varied diet, including plants such as seaweed and black crowberries, a wide range of birds and invertebrates, and carcasses of large mammal s such as seals, reindeer, and sheep. Marked seasonal, geographical an d inter-annual differences confirm arctic foxes in Iceland as opportun istic feeders. There are coastal and inland foxes: coastal foxes feed mainly on prey derived directly or indirectly from the ocean, particul arly various seabirds and seals, while inland foxes feed largely on mi grant birds, such as geese, waders and passerines in summer, and ptarm igan in winter. Despite their reputation for killing lambs. in this st udy, lamb carcasses were found at only 19.4% of 1125 fox dens, 44% of which had only one carcass. The distance to the nearest farm and the p hysical condition of lambs were major determinants of the number of ca rcasses found at a den. We discuss the implications of arctic foxes' d iet for population dynamics and group formation; and for management pr actices.