Willemsens Christina, Kerth Gerald, Hernández-Montero Jesús R
Zoological Institute and Museum, Applied Zoology and Nature Conservation, Greifswald University, Loitzer Straße 26, 17489, Greifswald, Germany.
Oecologia. 2025 Apr 2;207(4):58. doi: 10.1007/s00442-025-05700-9.
Roosts are a crucial resource for bats, which choose them based on many factors, including the surrounding habitat, microclimate, and space available for communal roosting. The latter is important because many bat species benefit from social thermoregulation by forming colonies in their roosts. However, it remains unclear whether bats can base their roost choice directly on the space available for roosting when other characteristics, such as roost microclimate do not vary. We present results from a field experiment in which RFID-tagged Bechstein's bats (Myotis bechsteinii) in a maternity colony were given paired bat boxes with identical external dimensions but differing internal roosting space. This allowed us to control for other factors that might influence roost choice and to record the bats' nightly visits to the boxes prior to their occupation as day roosts. To assess whether roost temperature influenced roost choice in our setup, we measured the internal temperature of the boxes. Female Bechstein's bats showed a clear preference for boxes with more roosting space, as evidenced by a higher frequency of nightly visits and more frequent use as day roosts. As there was no significant difference in temperature between boxes with different internal volumes, roost temperature cannot explain the bats' preference for spacious roosts in our experiment. Our data provide evidence that bats can directly assess the volume of their roosts. Our results are consistent with the argument that small volume roosts may limit roosting group size potentially reducing social thermoregulation benefits.
栖息地对蝙蝠来说是至关重要的资源，蝙蝠会基于许多因素来选择栖息地，包括周边栖息地、小气候以及可供群体栖息的空间。后者很重要，因为许多蝙蝠物种通过在栖息地形成群体而受益于社会体温调节。然而，当其他特征（如栖息地小气候）不变时，蝙蝠是否能直接依据可供栖息的空间来选择栖息地仍不清楚。我们展示了一项野外实验的结果，在该实验中，一个育幼群体中带有射频识别标签的贝希斯坦蝙蝠（Myotis bechsteinii）被给予了一对外部尺寸相同但内部栖息空间不同的蝙蝠箱。这使我们能够控制其他可能影响栖息地选择的因素，并记录蝙蝠在将这些箱子用作日间栖息地之前夜间对它们的访问情况。为了评估在我们的实验装置中栖息地温度是否影响栖息地选择，我们测量了箱子的内部温度。雌性贝希斯坦蝙蝠表现出对具有更多栖息空间的箱子有明显偏好，夜间访问频率更高以及更多地用作日间栖息地就是证明。由于不同内部容积的箱子之间温度没有显著差异，栖息地温度无法解释我们实验中蝙蝠对宽敞栖息地的偏好。我们的数据提供了证据表明蝙蝠能够直接评估其栖息地的容积。我们的结果与小容积栖息地可能限制栖息群体规模从而潜在减少社会体温调节益处的观点一致。
