不同栖居地和越冬时期长耳鸮的食物组成

Food composition of wintering long-eared owls(Asio otus) in different habitats in Beijing

通过分析2003—2006年连续3个冬季北京城区和城郊越冬长耳鸮的食团,研究了长耳鸮食物组成的时间与空间变化特征。每月收集1次长耳鸮食团,通过其内容物分析长耳鸮食物中的猎物种类和数量构成。结果表明:城区和城郊两地长耳鸮3种主要猎物中蝙蝠的被捕食率分别为41.6%和43.0%,鼠类为27.5%和39.4%,鸟类为30.7%和18.9%;城区和城郊长耳鸮的食物构成在2004—2005年与2005—2006年的冬季存在显著差异,初冬和冬末的食物构成差异也呈显著水平;同区域的长耳鸮食物构成在年度间和不同越冬时期皆存在显著差异;两地越冬长耳鸮捕食猎物比例的差异与生存环境中猎物资源的可获得性有关。

To understand the spatiotemporal variations of the food composition of wintering Asio otus in the urban and suburban areas of Beijing, the diets were collected monthly in the wintertime 2003-2006, with their composition analyzed. Among the three main preys in the urban and suburban areas of Beijing, bats occupied 41.6% and 43.0%, rodents occupied 27.5% and 39. 4%, and birds occupied 30. 7% and 18.9% , respectively. There were significant differences in the prey composition of A. otus between the urban and suburban areas in the wintertime 2004-2005 and 2005-2006, and between early winter and late winter. In the same areas, the prey composition also showed significant differences among years and among wintering periods. It was suggested that the difference in the predation rates of prey species by the wintering A. otus was related to the availability of prey resources in the habitats.