Diet of the White-tailed Eagle Haliaeetus albicilia in Finland

Abstract

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 in 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 frequencies of given types of prey, the proportion of fish being as much as 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 17% in Lapland. Temporal differences also occurred in the diet, Eiders and gulls, for example, increased in the diet in the archipelago regions, in parallel with prey population changes.