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，即可最大化自身适合度。个体在做出觅食决策时，需评估觅食收益，同时权衡被捕食者捕获的潜在风险。然而，目前尚未充分明确不同因素如何相互作用以影响此类决策，针对单个觅食者的相关研究尤甚。本研究以波多黎各的热带蜥蜴冠安乐蜥（Anolis cristatellus）为研究对象，采用觅食行为测定方法构建了一套标准化的操控性野外实验体系。我们为雄性冠安乐蜥提供觅食场景，以检验同种个体存在与否、捕食风险感知水平、食物丰度，以及上述因素间的交互作用如何决定觅食决策的结果。实验1结果显示，当食物匮乏且食槽附近存在同类时，冠安乐蜥的觅食速度更快；而当食物充足且无同类在场时，其摄食耗时更长。上述结果表明，冠安乐蜥的觅食决策是一套复杂过程的产物：个体在考量食物丰度的同时，借助同类个体传递的信息评估捕食风险。实验2中，我们通过调整至食槽的距离模拟捕食风险升高，结果显示个体对可用栖息台的选择与摄食潜伏期显著相关，证实了捕食风险感知的重要性。本研究发现，波多黎各冠安乐蜥会整合关于食物丰度、同类活动与捕食风险的实时生态信息，并据此调整觅食行为。