Multiple signaling in a variable environment: expression of song and color traits as a function of ambient sound and light

Many animals communicate using more than one signal, and several hypotheses exist to explain the evolution of multiple signals. However, these hypotheses typically assume static selection pressures and previous work has not addressed how spatial and temporal environmental variation can shape variation in signaling systems. In particular, environmental variability, such as ambient lighting or noise, may affect efficacy (e.g. detectability/perception by receivers) of signals. To examine how signal expression varies intraspecifically as a function of habitat characteristics, we evaluated relationships between spatial environmental variation and song and plumage color expression in a tropical songbird, the red-throated ant-tanager (Habia fuscicauda) in Panama. We recorded male ant-tanager song, plucked feathers to measure coloration, and recorded the acoustic and light environments from each male’s territory. In addition, we took several morphometric measurements from each male to assess th...诸多动物会借助多种信号开展通信，目前已有多项假说用于阐释多重信号的演化机制。然而，此类假说通常默认选择压力处于静态，且既往研究尚未探讨空间与时间维度的环境变异如何塑造信号系统的差异。具体而言，环境波动（如环境光照或噪声水平）可能会影响信号的传递效能，例如接收者的可检测性与感知能力。为探究信号表达如何随生境特征呈现种内变异，我们以巴拿马的热带鸣禽——红喉蚁唐纳雀（Habia fuscicauda）为研究对象，分析了空间环境变异与该物种鸣唱、羽色表达之间的关联。我们录制了雄性红喉蚁唐纳雀的鸣唱鸣声，采集羽毛样本以测定其羽色特征，并记录了每只雄鸟领地内的声学与光照环境。此外，我们还对每只雄鸟开展了多项形态测量，以评估……