Changes in the diet of the Golden Eagle Aquila chrysaetos and small game populations in Finland in 1957–1996

Abstract

Prey remains and pellets were collected in 1957-97 from the nest sites of the Golden Eagle in the Finnish reindeer husbandry area and in the area south of it. In addition to main prey, mountain hares and grouse, the Golden Eagle often catches also larger prey (Cranes, reindeer calves, adult red foxes), but also much smaller species (red squirrel, stoat, water vole, thrushes). Many waterfowl are included in the diet too, but only very few gulls. Diet percentages of grouse and cranes (51 % and 2%) are larger south of the reindeer area, where that of reindeer calves is about eight percent. The annual changes in the densities of mountain hares and grouse have caused corresponding changes in the percentages in the diet of the Golden Eagle. There are exceptions in these correlations between main prey and their percentages that are explained by the changes in the density of the other main prey. Waterfowl, corvids and red foxes are alternative prey in Finland. In other parts of Europe the main prey may include also hedgehogs, marmots and reptiles .