THE HUGEST WINTERING OF WHITE-SHOULDERED EAGLE AT KURIL LAKE (SOUTH KAMCHATKA)
A.V. Ladygin, E. G. Lobkov. 0.N. Ladygina
The wintering of 1989 in the lake Kuril (South Kamchatka) basin sheltered 650— 700 of the white-shouldered eagles, 20—25 golden eagles and 20—25 white-tailed eagles. It was the hugest wintering in the area of the species. The population peak was registered in December—January, and in March the wintering discharged. The eagles prefered after-spawring salmons (90% of their catch). Mass cleptoparasitism was ascertained. The eagles picked up nearly 4% of the total sock-eyed salmon population at the lake spawning grounds, and nearly 0,5% — at the river spawning grounds. During the winter eagles picked up nearly 15 thousand sock-eyed salmons (0,6% of the spawners). The impact of eagles upon the reproductive part of the sock-eyed salmon population was found to be inessential.