Coordination and information transfer in bat colonies with fission-fusion behaviour

为了获得最大范围的群体利益，群体生活的个体通常需要协调他们的活动。因此，了解动物群体协调的机制、原因和后果是行为生态学的核心焦点。我们的合作项目的目的是回答问题，在自然条件下，群体成员之间的信息传递导致群体协调，使用社区繁殖的贝希斯坦的蝙蝠，鼠耳蝠，作为一个模型。贝希斯坦的蝙蝠群落显示出裂变-融合行为，即，分裂成小组和重新合并的小组，几乎每天转换他们的公共日栖息地。群体成员协调它们在栖息地之间的集体运动，以确保公共栖息，这为它们提供了群体利益，如社会温度调节。尽管群体协调对于裂变融合社会的运作非常重要，并且在蝙蝠群体和其他动物社会中广泛发生裂变融合行为，但只有少数研究调查了野生裂变融合社会中的信息传递和群体协调。在这项实地研究中，我们调查如何贝希斯坦的蝙蝠殖民地协调他们的集体栖息地切换。我们使用最近建立的无线生物记录网络BATS（广泛适用的跟踪系统），自动收集蝙蝠的夜间遭遇和它们的栖息地外的运动的数据。为了在具有高裂变融合动力学的蝙蝠群体中协调集体栖息地转换方面提供新的见解，我们的研究旨在识别和量化个体用于寻找新栖息地和相互传递关于公共栖息地的信息的中心行为要素（例如，夜间接近栖息地，引导跟随行为，群集行为）。在田间实验的帮助下，我们的目标是评估协调过程的灵活性，特别是关于栖息地的类型（熟悉的栖息地与新的栖息地）和所涉及的个体的特征（例如，年龄、经验、亲属关系）。我们的项目可以建立在完全建立的现场是两个贝希斯坦的蝙蝠殖民地。这些殖民地已被监测长达27个连续的夏天。所有的群体成员都被单独标记了PIT标签，蝙蝠的人口统计学和遗传关系也得到了解决。该项目的重要性来自于一种新的尖端技术（BATS系统）与一种蝙蝠物种的特别长期实地数据集的结合，这种数据集有可能作为裂变-聚变动力学和群体协调行为的模型。我们的首要目标是提高对具有裂变-融合行为的动物社会功能的理解。

To gain the maximum range of grouping benefits, group-living individuals typically need to coordinate their activities. Understanding the mechanisms, the causes, and the consequences of group coordination in animals, is thus a central focus of behavioural ecology. Our collaborative project aims for answering the questions how under natural conditions information transfer among group members leads to group coordination, using the communally breeding Bechstein’s bat, Myotis bechsteinii, as a model. Bechstein’s bat colonies show fission-fusion behaviour, i.e., splitting into subgroups and re-merging of subgroups, which switch their communal day roosts almost daily. Colony members coordinate their collective movements between roosts to ensure communal roosting, which provides them with grouping benefits such as social thermoregulation. Despite the importance of group coordination for the functioning of fission-fusion societies and the widespread occurrence of fission-fusion behaviour in bat colonies and other animal societies, only a few studies investigated information transfer and group coordination in wild fission-fusion societies. In this field study, we investigate how Bechstein's bat colonies coordinate their collective roost-switching. We use the recently established wireless biologging network BATS (Broadly Applicable Tracking System) to automatically collect data of nightly encounters of bats and their movements outside their roosts. In order to provide new insights in the coordination of collective roost-switching in bat colonies with high fission-fusion dynamics our study aims on identifying and quantifying the central behavioural elements that individuals use to find novel roosts and transfer information about communal roosts among each other (e.g., nightly approaches to roosts, leading-following behaviour, swarming behaviour). With the help of a field experiment we aim on assessing the flexibility of the coordination process, in particular with respect to the type of roost (familiar vs. novel roost) and the traits of the individuals involved (e.g., age, experience, kinship). Our project can build upon fully established field sites that are home to two Bechstein's bat colonies. These colonies have been monitored for up to 27 consecutive summers. All colony members are individually marked with PIT-tags and the bats’ demography and genetic relationships have been resolved. The significance of the project arises from the combination of a new cutting-edge technology (BATS- system) with an extraordinary long-term field data set on a bat species which has the potential to serve as a model for fission-fusion dynamics and group coordination behaviour. Our overarching goal is to improve the understanding of the functioning of animal societies with fission-fusion behaviour.