Data from: Predation risk perception, food density and conspecific cues shape foraging decisions in a tropical lizard

When foraging, animals can maximize their fitness if they are able to tailor their foraging decisions to current environmental conditions. When making foraging decisions, individuals need to assess the benefits of foraging while accounting for the potential risks of being captured by a predator. However, whether and how different factors interact to shape these decisions is not yet well understood, especially in individual foragers. Here we present a standardized set of manipulative field experiments in the form of foraging assays in the tropical lizard Anolis cristatellus in Puerto Rico. We presented male lizards with foraging opportunities to test how the presence of conspecifics, predation-risk perception, the abundance of food, and interactions among these factors determines the outcome of foraging decisions. In Experiment 1, anoles foraged faster when food was scarce and other conspecifics were present near the feeding tray, while they took longer to feed when food was abundant and when no conspecifics were present. These results suggest that foraging decisions in anoles are the result of a complex process in which individuals assess predation risk by using information from conspecific individuals while taking into account food abundance. In Experiment 2, a simulated increase in predation risk (i.e., distance to the feeding tray) confirmed the relevance of risk perception by showing that the use of available perches is strongly correlated with the latency to feed. We found Puerto Rican crested anoles integrate instantaneous ecological information about food abundance, conspecific activity and predation risk, and adjust their foraging behavior accordingly.

动物在觅食过程中，若能根据当前环境条件调整觅食决策，便可最大化自身适合度。个体在制定觅食决策时，需评估觅食收益，同时权衡被捕食者捕获的潜在风险。然而，不同因素如何交互作用以塑造此类觅食决策，目前尚未得到充分阐释，针对单个觅食者的相关研究尤甚。
本研究以波多黎各的冠安乐蜥（Anolis cristatellus）为研究对象，采用标准化的野外操控实验——以觅食行为测定（foraging assays）的形式开展——为雄性安乐蜥提供觅食机会，以探究同种个体存在与否、捕食风险感知、食物丰度，以及这些因素间的交互作用如何决定觅食决策的结果。
在实验1中，当食物匮乏且喂食托盘附近存在同种个体时，安乐蜥的觅食速度更快；而当食物充足且无同种个体在场时，其进食耗时更长。上述结果表明，安乐蜥的觅食决策是一个复杂过程的产物：个体在考量食物丰度的同时，会利用同种个体的相关信息评估捕食风险。
在实验2中，我们通过模拟提升捕食风险（即调整至喂食托盘的距离），结果显示受试个体对可用停落位点的选择与进食潜伏期呈显著相关，从而证实了风险感知的重要性。
本研究发现，波多黎各冠安乐蜥会整合关于食物丰度、同种个体活动及捕食风险的即时生态信息，并据此调整自身的觅食行为。