In anthropogenic landscapes, aerial insectivores are often confronted with variable habitat complexity, which may influence the distribution of prey. Yet, high mobility may allow aerial insectivores to adjust their foraging strategy to different prey distributions. We investigated whether aerial‐hunting common noctules Nyctalus noctula adjust their foraging strategy to landscapes with different habitat complexity and assumingly different prey distribution. We hypothesized that the movement behaviour of hunting common noctules and changes of movement behaviour in reaction towards conspecifics would depend on whether they hunt in a structurally poor cropland dominated landscape or a structurally rich forest dominated landscape. We tracked flight paths of common noctules in northeastern Germany using GPS loggers equipped with an ultrasonic microphone that recorded foraging events and presence of conspecifics. Above cropland, common noctules hunted mainly during bouts of highly tortuous and area restricted movements (ARM). Bats switched from straight flight to ARM after encountering conspecifics. In the forested landscape, common noctules hunted both during ARM and during straight flights. The onset of ARM did not correlate with the presence of conspecifics. Common noctules showed a lower feeding rate and encountered more conspecifics above the forested than above the cropland dominated landscape. We conjecture that prey distribution above cropland was patchy and unpredictable, thus making eavesdropping on hunting conspecifics crucial for bats during search for prey patches. In contrast, small scale structural diversity of the forested landscape possibly led to a more homogeneous prey distribution at the landscape scale, thus enabling bats to find sufficient food independent of conspecific presence. This suggests that predators depending on ephemeral prey can increase their foraging success in structurally poor landscapes by using social information provided by conspecifics. Hence, a minimum population density might be obligatory to enable successful foraging in simplified landscapes.

中文翻译：

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景观结构影响食虫蝙蝠中社会信息的使用

在人为景观中，空中食虫动物经常面临生境复杂性的变化，这可能会影响猎物的分布。然而，高机动性可能使食虫动物将其觅食策略调整为不同的猎物分布。我们研究了空中狩猎常见是否noctules华山蝠调整其觅食策略，以适应具有不同栖息地复杂性和假设猎物分布不同的景观。我们假设狩猎普通结节的运动行为和对特定物种的反应的运动行为的变化将取决于它们是在结构贫困的农田占主导的景观还是在结构丰富的森林占主导的景观中狩猎。我们使用配备了超声波麦克风的GPS记录仪跟踪了德国东北部常见夜蛾的飞行路线，该超声波记录仪记录了觅食事件和特定物种的存在。在农田上空，常见结节主要是在高度曲折和区域受限运动（ARM）的回合中狩猎的。遇到特殊情况后，蝙蝠从直线飞行切换到ARM。在森林景观中 在ARM和直航期间都发现了常见的结节。ARM的发作与同种的存在无关。常见的夜蛾显示出较低的进食速度，并且在森林上方比在农田占主导的景观上方遇到更多的物种。我们推测，猎物在农田上的分布是零散且不可预测的，因此，在寻找猎物斑块期间，窃听猎物对蝙蝠至关重要。相反，森林景观的小规模结构多样性可能导致猎物在景观尺度上的分布更加均匀，从而使蝙蝠能够独立于特定物种而找到足够的食物。这表明依赖临时性猎物的捕食者可以通过使用物种提供的社会信息来增加在结构恶劣的景观中觅食的成功率。因此，必须有最低人口密度才能在简化的景观中成功觅食。