广西扁颅蝠与褐扁颅蝠的食物选择

2002年3～10日在广西南宁地区的宁明县和龙州县，用超声波监测和网捕法确定扁颅蝠与褐扁颅蝠的捕食区，在捕食区内用粘捕法调查潜在的食物量；用粪便分析法确定食物组成。在宁明县和龙州县扁颅蝠和褐扁颅蝠的潜在食物量都是以双翅目昆虫为主(45．93％以上)，其次为鞘翅目(12．59％以上)和膜翅目(7．47％以上)；但双翅目、膜翅目在两地差异显著。宁明县扁颅蝠的食物组成以双翅目(40．33％)和膜翅目(38．46％)为主，鞘翅目(16．07％)次之；龙州县扁颅蝠和褐扁颅蝠食物组成中以膜翅目(63．37％，62．34％)为主，其次为双翅目(21．57％，29．62％)、鞘翅目(11．59％，5．96％)；对比两地扁颅蝠的食物组成发现，膜翅目和双翅目差异极显著。对比食物组成与潜在食物量发现，两种蝙蝠对膜翅目为正选择，对其他目负选择或无选择，均为选择性捕食者。

Prey Selection of Tylonycteris pachypus and T.robustula(Chiroptera:Vespertilioninae) in Guangxi,China

We confirmed the foraging sites of Tylonycteris pachypus and T.robustula using echolocation detecting and mist net catching,measured the potential food (insects) availability in the bats' foraging area by sticky traps,and analyzed the bats' food components using fecal analysis in Ningming County and Longzhou County,Nanning District,Guangxi Province,China,in the period from March to October,2002.We found that Diptera (above 45 93%,by volume per cent),Coleoptera (above 12 59%) and Hymenoptera (above 7 47%) were important in both Ningming County and Longzhou County,but Diptera and Hymenoptera were significant different between two counties.The results indicated that Diptera (40 33% by volume per cent) and Hymenoptera (38 46%) were important in the food components of T.pachypus in Ningming County,following by Coleoptera (16 07%);while Hymenoptera (63 37%,62 34% respectively) was important in the food components of both T.pachypus and T.robustla in Longzhou County,following by Diptera (21 57%,29 62%) and Coleoptera (11 59%,5 96%).The food components of T.pachypus in Ningming County also consisted of Hemiptera (2 55%),Homoptera (0 93%),Orthoptera (0 74%),Blattodea (0 52%),Ephemeroptera (0 23%) and Embioptera (0 17%);in Longzhou County also consisted of Hemiptera (1 77%),Homoptera (1 21%),Orthoptera (0 35%) and Trichoptera (0 14%).The food components of T.robustula in Longzhou County also consisted of Hemiptera (1 54%),Orthoptera (0 26%),Trichoptera (0 16%) and Ephemeroptera (0 16%).Comparing the food components of T.pachypus between Ningming County and Longzhou County,we found that Hymenoptera and Diptera were significant different.Comparing the food components of bats by fecal analysis with the potential food availability captured in the foraging area,we found that both species of bats positively selected Homoptera,but negatively selected other orders of insects,so both species of bats were prey selectors.