Data from: Deceiving predators: linking distraction behavior with nest survival in a ground-nesting bird

Individual behavior that minimizes predation risk is favored by natural selection. Ground-nesting birds employ different defensive behaviors as part of their antipredator strategies because they nest where a wide range of predators have access. We investigated the influence of distraction displays on breeding success in the Kentish Plover, Charadrius alexandrinus, in order to explore the role of the defensive behavior on nest survival. We quantified the intensity of defensive behavior of adult plovers in response to nest disturbance caused by an approaching researcher, by ranking display types according to the intensity and exposure to predation. We also examined sex differences in nest defense to determine whether the existence, intensity, and consistency of individual defensive behaviors could have an impact on nest survival. We used the nest survival model in Program MARK to estimate daily survival rates of nests and to examine the influence of temporal, behavioral, and habitat variables on nest success. Our results show a positive correlation between male and female defense behaviors within pairs and that nests in which parents invested more on defense survived longer. Nevertheless, there were differences in the risks assumed by the 2 members of breeding pairs in nest defense, with females performing riskier defensive behaviors than males. The top-ranked nest survival models included combined additive effects of site, season, habitat type, nest exposure, and the defense behavioral response of females as best predictors. Finally, our study highlights that increased risk assumption in offspring defense is advantageous in terms of individual fitness.

能够降低被捕食风险的个体行为，会受到自然选择的青睐。地面筑巢鸟类作为其反捕食策略的组成部分，会采用多种防御行为——究其原因，这类鸟类的筑巢区域可被众多捕食者涉足。本研究以环颈鸻（Kentish Plover，学名Charadrius alexandrinus）为研究对象，探究干扰炫耀行为对其繁殖成功率的影响，以明确防御行为在鸟巢存活中的作用。我们通过依据行为强度与被捕食暴露风险对干扰炫耀行为类型进行分级，量化了成年环颈鸻在应对接近的研究人员所引发的鸟巢干扰时的防御行为强度。此外，我们还分析了鸟巢防御行为中的性差异，以探究个体防御行为的有无、强度及一致性是否会对鸟巢存活产生影响。我们使用MARK程序（Program MARK）中的鸟巢存活模型，估算鸟巢的日存活率，并分析时间、行为与栖息地变量对鸟巢繁殖成功率的影响。研究结果显示，配对的雌雄个体间的防御行为呈正相关，且亲代投入更多防御行为的鸟巢存活时长更长。尽管如此，繁殖配对的雌雄个体在鸟巢防御中承担的风险存在差异：雌性个体实施的防御行为比雄性更具危险性。最优鸟巢存活模型将样地、繁殖季、栖息地类型、鸟巢暴露程度以及雌性的防御行为响应作为最佳预测因子，纳入其联合加性效应。最后，本研究表明，在后代防御中承担更高风险，对个体的适合度具有增益效应。