Data from: Plasticity of parental care under the risk of predation: how much should parents reduce care?

Predation can be an important agent of natural selection shaping parental care behaviours, and can also favor behavioural plasticity. Parent birds often decrease the rate that they visit the nest to provision offspring when perceived risk is high. Yet the plasticity of such responses may differ among species as a function of either their relative risk of predation, or the mean rate of provisioning. Here, we report parental provisioning responses to experimental increases in the perceived risk of predation. We tested responses of 10 species of birds in north temperate Arizona and subtropical Argentina that differed in their ambient risk of predation. All species decreased provisioning rates in response to the nest predator but not to a control. However, provisioning rates decreased more in species that had greater ambient risk of predation on natural nests. These results support theoretical predictions that the extent of plasticity of a trait that is sensitive to nest predation risk should vary among species in accordance with predation risk.捕食作用可作为塑造亲本抚育行为的重要自然选择动因，同时也会推动行为可塑性（behavioural plasticity）的演化。当亲鸟感知到较高捕食风险时，通常会降低往返巢穴投喂幼鸟的频次。然而，这类响应的可塑性可能因物种而异，且与物种自身的相对捕食风险水平或平均育雏投喂速率相关。本研究报道了亲鸟育雏投喂行为对实验性升高的感知捕食风险的响应模式。我们以栖息于北温带亚利桑那州与亚热带阿根廷的10种鸟类为研究对象，这些物种的天然本底捕食风险水平存在差异。所有受试物种在模拟巢捕食者的处理下均降低了育雏投喂速率，而在对照处理中未出现此类变化。不过，天然巢穴面临更高捕食风险的物种，其育雏投喂速率的下降幅度也更为显著。本研究结果印证了相关理论预测：对巢穴捕食风险敏感的性状，其可塑性程度应随物种所处的捕食风险水平不同而产生差异。