DIET OF THE WHITE-TAILED EAGLE HALIAEETUS-ALBICILLA IN FINLAND

The White-tailed Eagle nests in the Aland Islands (and SW archipelago) and the islands of the Quark region in Finland, and also close to the large reservoirs in Lapland. Prey remains collected from nest sites i n these areas in 1978-90 indicate that birds constitute on average 51% of the prey, fish 42% and mammals only 7%. Pike constituted some 33% of the prey. Some large regional differences were observed in the freq uencies of given types of prey, the proportion of fish being as much a s 67% in Lapland but only 32% in the Quark region and 27% in the Aland Islands, while the opposite trend was observed in the case of birds ( 29%, 59% and 65%, respectively). The birds were primarily composed of Anatidae, which constituted 51% of all prey in the Aland Islands and 1 7% in Lapland. Temporal differences also occurred in the diet, Elders and gulls, for example, increased in the diet in the archipelago regio ns, in parallel with prey population changes.