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，理解动物群体协调的机制、原因和后果是行为生态学的中心焦点。我们的合作项目旨在回答在自然条件下群体成员之间的信息传递如何导致群体协调的问题，以集体繁殖的贝克斯坦蝙蝠Myotis bechsteinii为模型。Bechstein的蝙蝠群体表现出裂变-融合行为，即分裂成亚群，并重新合并亚群，这些亚群几乎每天都会改变它们的公共白天栖息地。蜂群成员协调它们在栖息地之间的集体行动，以确保公共栖息地，这为它们提供了群体利益，如社会体温调节。尽管群体协调对于裂变聚变社会的运作很重要，而且在蝙蝠群体和其他动物社会中普遍存在裂变聚变行为，但只有几项研究调查了野生裂变聚变社会中的信息传递和群体协调。在这项实地研究中，我们调查了Bechstein的蝙蝠群体如何协调它们的集体栖息地转换。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)来自动收集蝙蝠夜间接触的数据及其在栖息地外的活动。为了对具有高裂变-聚变动力的蝙蝠群体中集体栖息地切换的协调提供新的见解，我们的研究旨在识别和量化个体用来寻找新栖息地和彼此之间传递关于公共栖息地的信息的中央行为元素(例如，夜间栖息地的方法、领头跟随行为、集群行为)。在实地实验的帮助下，我们旨在评估协调过程的灵活性，特别是关于栖息地的类型(熟悉的栖息地与新栖息地)和所涉个体的特征(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野外场地上，这些场地是两个贝克斯坦蝙蝠群体的家园。这些蜂群已经连续监测了长达27个夏天。所有的群体成员都被单独地标记了坑标签，蝙蝠的人口统计学和遗传关系已经得到解决。该项目的重要性源于一项新的尖端技术(BATS系统)与关于蝙蝠物种的特别长期现场数据集的结合，该数据集有可能成为裂变-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.