Foraging activity and food resource use of Brazilian free-tailed bats, Tadarida brasiliensis (Molossidae)
Foraging activity and food resource use of Brazilian free-tailed bats, Tadarida brasiliensis (Molossidae)
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巴西无尾蝙蝠 Tadarida brasiliensis（Molossidae）的觅食活动和食物资源利用
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
G. McCracken
中科院分区：
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作者：
Y. Lee;G. McCracken
摘要我们研究了觅食活动和食物资源利用的巴西无尾蝙蝠，Tadarida brasiliensis，从一个大的产妇殖民地附近的Uvalde，得克萨斯州。我们记录了回声定位蝙蝠在城镇，农田和牧场的复制网站的呼叫和量化的比例信号接收时间，喂养嗡嗡声的数量，和平均攻击尝试每单位的活动时间，以评估栖息地的蝙蝠使用。蝙蝠的食物习惯，确定从粪便样品，并在三个栖息地的各种昆虫目的组成和相对丰度进行了评估，使用灯光陷阱。有汞蒸汽型路灯的城镇似乎是蝙蝠的重要觅食区，在那里它们表现出比农田或牧场更高的觅食活动和攻击率。然而，在城镇路灯的共同使用，可能会影响我们的陷阱在昆虫评估的效率，城镇表现出较低的相对昆虫丰度比其他两个栖息地。昆虫丰度没有不同的牧场和农田之间，但相对昆虫丰度下降发生在黎明前的时期在农田，这与较高的蝙蝠活动每单位时间在牧场比农田。蝙蝠也显示出更高的攻击率，并有一个更广泛的饮食，在晚上比在黎明前的时期。蝙蝠的食物中含有12个昆虫目，占陷阱捕获昆虫目的80%。在序数水平上，这些猎物在蝙蝠饮食中的相对重要性与陷阱采样的猎物密切相关。午夜和黎明前采样之间主要昆虫目相对丰度的差异也与蝙蝠饮食中相应昆虫目的百分比体积相关。这些结果与我们的预测一致，并建议该物种的机会主义觅食模式。
Abstract We studied foraging activity and food resource use of Brazilian free-tailed bats, Tadarida brasiliensis, from a large maternity colony near Uvalde, Texas. We recorded echolocation calls of bats at replicate sites in towns, cropland, and ranches and quantified the proportions of signal-receiving time, the numbers of feeding buzzes, and the mean attack attempts per unit of activity time to evaluate habitat use by bats. Food habits of the bats were determined from fecal samples, and the composition and relative abundance of various insect orders in the three habitats were assessed using light traps. Towns with mercury-vapor type street lamps appeared to be important feeding areas for the bats, where they exhibited higher foraging activity and attack rates than over cropland or ranches. The common use of street lamps over towns, however, could have affected the efficiency of our traps in insect assessment; towns exhibited lower relative insect abundance than the other two habitats. Insect abundance did not differ between ranches and cropland, but a decline in relative insect abundance occurred in pre-dawn periods over cropland, which correlated to a higher bat activity per unit time over ranches than on cropland. The bats also displayed higher attack rates, and had a broader diet, in evening than in pre-dawn periods. The diet of bats contained 12 orders of insects, which accounted for 80% of insect orders captured in traps. At the ordinal level, the relative importance of these prey in the bats’ diet strongly correlated to those sampled by the traps. The differences in relative abundance of major insect orders between midnight and pre-dawn sampling also correlated to those in percent volumes of respective insect orders in the bats’ diet. These results agree with our prediction and suggest an opportunistic foraging mode for this species.