Diet and breeding success of the Golden Eagle in Finland 1958-82

The diet and breeding success of the Golden Eagle nesting in northern Finland has been studied yearly since 1958. The Arctic Hare and Capercaillie are the main prey species, about 25 % each. Tetraonids in total make up about 50 %. 9 % of the prey individuals are reindeer calves. The Capercaillie is captured relatively more often than the Black Grouse or Willow Grouse in relation to the densities of the respective populations. The yearly changes in tetraonid and hare populations induce corre sponding fluctuations in their percentages in the food of the eagle. The reproductive success of the Golden Eagle in Finland was a little better in 1971-77 than in 1960-67. The brood size and breeding success per pair in Finland and Sweden correspond to figures for areas with rich prey resources in central Europe.