Prey detection in trawling insectivorous bats: duckweed affects hunting behaviour in Daubenton's bat, Myotis daubentonii
Prey detection in trawling insectivorous bats: duckweed affects hunting behaviour in Daubenton's bat, Myotis daubentonii
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DOI：
10.1007/s002650050521
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发表时间：
1998-12-01
影响因子：
2.3
通讯作者：
van de Grind, WA
中科院分区：
文献类型：
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作者：
Boonman, AM;Boonman, M;van de Grind, WA
多氏蝙蝠，一种拖网蝙蝠，捕食靠近水面飞行或在水面上休息的昆虫。在夏季，多瓦龙蝙蝠捕食的许多池塘逐渐被浮萍覆盖。本研究的目的是调查浮萍覆盖的Daukon的蝙蝠的狩猎行为和超声波反射性能的水面上的影响。我们的研究揭示了以下内容。(1)杜氏蝙蝠避开覆盖着浮萍的水面。(2)猎物丰富度与觅食的Daughton蝙蝠的数量有关，但独立的浮萍覆盖。(3)当粉虫之间的标准化量的浮萍自然觅食Dauzion的蝙蝠，他们抓住了显着减少粉虫时，浮萍覆盖增加。(4)超声波信号的测量结果表明，覆盖有浮萍的水面在小角度（即平行于水面）返回一个更强的背景回波相比，未覆盖的水面。看起来很可能是水面上的一层浮萍通过掩盖猎物返回的回声来干扰猎物的探测。(5)对蝙蝠来说，区分小块的浮萍和粉虫相对困难。这种拖网蝙蝠物种的拟议的歧视机制表明，单一的浮萍补丁也可以被Daughton的蝙蝠误认为是自然猎物。
Daubenton's bat, a trawling vespertilionid bat species, hunts for insects that fly close to, or rest on, the water surface. During summer, many ponds at which Daubenton's bats hunt become gradually covered with duckweed. The purpose of this study was to investigate the effects of duckweed cover on the hunting behaviour of Daubenton's bats and on the ultrasound-reflecting properties of the water surface. Our study revealed the following. (1) Daubenton's bat avoids water surfaces covered with duckweed. (2) Prey abundance was related to the number of foraging Daubenton's bats but was independent of duckweed cover. (3) When mealworms were presented among standardized amounts of duckweed to naturally foraging Daubenton's bats, they caught significantly less mealworms when the duckweed cover was increased. (4) Measurements with ultrasonic signals show that a water surface covered with duckweed returns a much stronger background echo at small angles (i.e. parallel to the water surface) compared to an uncovered water surface. It seems likely that a cover of duckweed on the water surface interferes with prey detection by masking the echoes returning from prey. (5) It was relatively difficult for the bats to discriminate small patches of duckweed from mealworms. The proposed discrimination mechanism for this trawling bat species suggests that single duckweed patches can also be mistaken for natural prey by Daubenton's bats.