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.在同一生物群落中，不同物种可能面临相似的捕食风险，因此物种传递与解读异种威胁信息的能力，或为决定物种间关联模式的核心因素。本研究结合观测、实验与系统发育（phylogenetic）研究方法，旨在探究亚马孙低地鸟类群落中，进化历史与功能性状在多大程度上调控物种的集群倾向（flocking propensity）以及捕食风险感知——即对异种报警鸣声（heterospecific alarm calls）的响应。我们提出如下预测：在开阔地带取食且觅食视野受限的小型鸟类，其集群倾向更高，且在对报警声的正向响应中占比更高。基于56个物种的数据集，本研究采用广义线性模型（generalized linear models）并整合系统发育信息进行分析，结果显示：系统发育关系、体型大小、觅食高度、植被密度以及对报警声的响应，均会显著影响物种的集群倾向。与之相对，系统发育关系并未对物种响应异种报警鸣声产生显著作用。不过在功能性状维度中，觅食策略、觅食密度与集群倾向能够部分解释物种对报警声的响应机制。本研究结果表明，集群倾向与捕食风险感知呈显著正相关，且功能生态性状与进化历史可部分解释物种间的关联格局。