Data from: From resource to female defence – the impact of roosting ecology on a bat’s mating strategy

With their extraordinary species richness and diversity in ecological traits and social systems bats are a promising taxon for testing socio–ecological hypotheses in order to get new insights into the evolution of animal social systems. Regarding its roosting habits, proboscis bats form an extreme by occupying sites which are usually completely exposed towards daylight. This is accompanied by morphological and behavioural adaptations to remain cryptic in exposed day roosts. With long–term behavioural observations and genetic parentage analyses of individually marked proboscis bats we assessed its social dispersion and male mating strategy during day and night. Our results reveal nocturnal male territoriality – a strategy which most closely resembles a resource–defence polygyny that is frequent also in other tropical bats. Its contrasting clumped social dispersion during the day is likely the result of strong selection for crypsis in exposed roosts and is accompanied by direct female–defence in addition to male territoriality. To our knowledge, such contrasting male mating strategies within a single day–night–cycle have not been described in a vertebrate species so far and illustrate a possible evolutionary trajectory from resource–defence to female–defence strategy by small ecologically–driven evolutionary steps.蝙蝠拥有极高的物种丰富度，且在生态性状与社会系统方面呈现出丰富多样性，因此是检验社会生态学（socio-ecological）假说、为动物社会系统演化研究提供全新视角的极具潜力的分类单元（taxon）。就其栖息习性而言，长鼻蝠（proboscis bats）的栖息环境极为特殊：它们通常选择完全暴露于日光之下的栖息位点。为在暴露的日间栖息场所保持隐蔽，它们演化出了相应的形态与行为适应性特征。我们通过对个体标记的长鼻蝠开展长期行为观测与亲权遗传分析，评估了该物种在昼夜周期下的社会空间分布模式与雄性交配策略。研究结果显示，雄性个体存在夜行性领域行为，该策略与其他多数热带蝙蝠中常见的资源防御型一夫多妻制高度相似。与之形成鲜明对比的是，该物种日间呈现聚集型社会分布模式，这很可能是暴露栖息场所对隐蔽性产生强烈选择压力的结果；除雄性领域行为外，同时还伴随直接的雌性防御行为。据我们所知，目前尚未在脊椎动物中发现单一昼夜周期内存在此类截然不同的雄性交配策略的物种，该发现也阐释了通过生态驱动的微小演化步骤，从资源防御型交配策略向雌性防御型策略演化的潜在路径。