【摘要】 20 0 2年 5月至 2 0 0 3年 11月初 (冬眠期除外 ) ,约每两周一次 (每次调查持续 1- 2晚 )于北京房山霞云岭乡四合村蝙蝠洞 (115°5 9′N ,39°4 3′E)捕捉觅食后返洞的大足鼠耳蝠 (Myotisricketti) ,通过 2 8次野外调查收集了 342个粪便样品 ,分析了其食物组成的频率差异。北京地区大足鼠耳蝠主要捕食宽鳍 (Zaccoplaty pus) (在总样品中的频率为 6 0 2 % )、鲫鱼 (Carassiusauratus) (5 8% )和洛氏 (Phoxinuslagowskii) (2 3% )三种淡水鱼 ;还捕食至少 7个目的昆虫 ,分别为鞘翅目 (2 0 2 % )、鳞翅目 (12 6 % )、同翅目 (9 6 % )、蜉蝣目(4 1% )、半翅目 (5 6 % )、双翅目 (3 5 % )和膜翅目 (2 6 % )。两年中三种淡水鱼的总频率与昆虫的总频率差异显著 ;年内数据比较显示 ,鱼类和昆虫频率 2 0 0 2年差异不显著 ,2 0 0 3年差异显著。大足鼠耳蝠雨季和旱季食物种类基本无差异 ,但鱼类和昆虫在其食物组成中有年内波动 ,即大足鼠耳蝠旱季多以鱼类为食 ,雨季捕获昆虫的数量相对增加。据两年的研究结果 ,证实北京房山霞云岭大足鼠耳蝠的食物主要组成部分是三种鱼类 ,而宽鳍为主要食物成分的原因是其多在水体浅层活动而易被大足鼠耳蝠捕获。从能量收支平衡的角度推测大足鼠耳蝠在雨季捕食昆虫可能更多还原

【Abstract】 From May 2002 to November 2003 (skipping the period of hibernation),342 fecal samples were collected in 28 times about biweekly investigations to analyze the dietary characteristics of Myotis ricketti roosting in a big cave of Xiayun Ling of Fangshan District in Beijing (115°59′N,39°43′E); and the frequency were used to evaluate the major food items and the seasonal variation.A reservoir about 15 000 m2 was near the roosting cave with the Rickett’s big-footed bat.Referred specimen of insects and fish were collected at the time of field investigations.Examination of fecal pellets indicated that the big-footed bat consumed mainly three kinds of freshwater fish (68.3% occurring frequency of total samples,with Zacco platypus 60.2%,Carassius auratus 5.8% and Phoxinus lagowskii 2.3%); numerous insects fragments belonging to seven orders were identified,i.e.,Coleoptera (20.2%),Lepidoptera (12.6%),Homoptera (9.6%),Ephemeroptera (4.1%),Hemiptera (5.6%),Diptera (3.5%) and Hymenoptera (2.6%).The difference of frequency between fish and insects was significant in the two years compared,and the same result was found in 2003,but the difference was not significant in 2002.Fish was found in 28 collections.The difference of prey species was not significant between wet season and dry season,although there were a few more fragments of insects than of fish from the middle of June to August (wet season).The frequency indicated the occurrence of food items in the fecal samples and implied the preference of the animal for these prey; and Z.platypus is the major food item of M.ricketti because this fish species seeks food near the surface of water and jumpsinto the air,providing important cues for the big-footed bat which detect them by echolocation.By examining fecal samples,the present study determined that M.ricketti fed significantly on fish and could adjust the diet in wet season to some degree according to the availability of habitat更多还原