Data from: Functional traits, flocking propensity and perceived predation risk in an Amazonian understory bird community

Within a community, different species might share similar predation risks, and thus the ability of species to signal and interpret heterospecific threat information may determine species' associations. We combined observational, experimental and phylogenetic approaches to determine the extent to which evolutionary history and functional traits determined flocking propensity and perceived predation risk (response to heterospecific alarm calls) in a lowland Amazonian bird community. We predicted that small birds that feed myopically and out in the open would have higher flocking propensities and account for a higher proportion of positive responses to alarms. Using generalized linear models and the incorporation of phylogeny on data from 56 species, our results suggest that phylogenetic relationships alongside body size, foraging height, vegetation density and response to alarm calls influence flocking propensity. Conversely, phylogenetic relationships did not influence response to heterospecific alarm calls. Among functional traits, however, foraging strategy, foraging density and flocking propensity partially explained responses to alarm calls. Our results suggest that flocking propensity and perceived predation risk are positively related and that functional ecological traits and evolutionary history may explain certain species' associations.在一个生物群落中，不同物种可能面临相似的捕食风险，因此物种传递和解读异种（heterospecific）威胁信息的能力，或许决定了物种间的关联模式。本研究结合观测、实验与系统发育（phylogenetic）分析方法，旨在探究在亚马孙低地鸟类群落中，进化历史与功能性状（functional traits）对物种集群倾向（flocking propensity）以及感知捕食风险（perceived predation risk，即对异种警报鸣叫的响应）的影响程度。本研究预测，那些在开阔地带活动且采取近距离觅食策略的小型鸟类，会拥有更高的集群倾向，且对警报鸣叫做出正向响应的比例也更高。本研究基于56个物种的数据集，结合广义线性模型（generalized linear models）与系统发育校正分析，结果显示：系统发育关系、体型大小、觅食高度（foraging height）、植被密度（vegetation density）以及对警报鸣叫的响应，均会对物种的集群倾向产生影响。与之相反，系统发育关系并不会影响物种对异种警报鸣叫的响应。不过在功能性状中，觅食策略（foraging strategy）、觅食密度（foraging density）与集群倾向能够部分解释物种对警报鸣叫的响应。本研究结果表明，集群倾向与感知捕食风险呈正相关，且功能生态性状与进化历史能够在一定程度上解释物种间的关联模式。