독수리 11개체에 GPS를 부착하여 비행특성을 분석하였다. 한국에 월동기간은 평균 131일 (SD=17.4)이었고, 평균 비상 비율은 19.6%이었다. 비행고도는 100 m 이하가 21.6%이었으며, 101~200 m는 25.3%, 201~300 m는 19.0% 로, 300 m 이하가 65.9%이었다. 시간대별 비상률과 고도는 양의 상관관계 (r=0.929)를 보였고, 월별 비행고도 비율은 대부분 101~200 m에 가장 많은 비율을 나타냈다 (p<0.05). 월동기 독수리는 비행비율을 낮추고 300 m 이하 고도에서 비행하였다. 독수리의 넓은 행동권, 높은 비 행비율, 높은 고도 비행특성은 사회적 상호작용에 의해 먹이를 찾는 효율적인 비행방법으로 판단된다.

Cannibalism is a widely observed phenomenon in the animal kingdom. However, it is rarely found among birds outside nests in the wild because it occurs irregularly and it is almost impossible to monitor animal behavior constantly. On 17 January 2017, this behavior was directly observed from a group of vultures feeding on a conspecific in a paddy field near Lake Geumho in Haenam-gun (34°35ʹ58.25ʺ N, 126°26ʹ57.64ʺ E). It was observed and recorded with the binoculars and a camera with a telephoto lens in a car approximately 20 m (or 60 m) away from the site. The observer approached the feeding site after the last vulture had finished feeding and flown away and found remains of a vulture, including body feathers, skull, sterna keel, and both legs. It was the first report of cannibalism in Cinereous vulture Aegypius monachus in its overwintering grounds. The remaining skeleton was very fleshy, and the surrounding grass was wet with the blood of vulture. No other traces of a mammal or bird that could have been the vultures’ prey were found. This report provides a detailed account of the events related to this rare observation and the causes that might have led to it.