荣成天鹅湖湿地越冬大天鹅食性分析

Food Habits of Whooper Swan in Winter at the Tian'ehu of Rongcheng

2005年12月～2006年3月以大天鹅(Cygnus cygnus)为对象,研究其越冬期间的食性,利用粪便显微组织分析法定量调查其食物组成。结果表明,大天鹅的越冬食物主要为小麦(Triticum aestivum)、海带(Laminaria japonica)和大叶藻(Zostera marina),其中,小麦的比例最大,分别占冬季食物组成的99.67%和早春的90.17%。对冬季与早春的食物组成的差异进行分析,发现大天鹅在天鹅湖保护区发生了食物替代现象。结合以往资料,认为生态污染和湿地结构性破坏导致大天鹅传统食物减少,致使食物替代现象的发生。

Diet composition of Whooper Swan （Cygnus cygnus ） in winter was studied by the method of fecal microscopic analysis from December 2005 to March 2006. Results showed that Whooper Swan fed on mainly wheat, kelp and eelgrass. Wheat is accounted for 99.67 % of food items in winter and 90.17 % in early spring. By analyzing the diet differences between winter and early spring and with the results of previous studies, we found that the main original food item eelgrass had been substituted by wheat. This result implied that environmental pollution and wetland destruction might be responsible for the rapid decline of originam food supply to Whooper Swan.