Anti-predator function of not covering eggs in the initial phase of nesting in Grey Partridge <i>Perdix perdix</i>: a field experiment

<b>Capsule:</b> An experiment in the field supports the hypothesis that Grey Partridges <i>Perdix perdix</i> purposely expose their first laid eggs in order to test the predation risk at their nest site. <b>Aims:</b> To test the hypothesis that female Grey Partridges leave first laid eggs uncovered to assess the predation risk at their chosen nesting site. <b>Methods:</b> Four area-independent experiments with artificial nests were used. Predation risk was estimated by daily nest failure rate. Generalized linear mixed-effects models were used in statistical analysis. <b>Results:</b> We found that Grey Partridge females could predict nest site safety. At nest sites where the first uncovered egg was depredated, there was a higher predation risk for the whole clutch. <b>Conclusion:</b> Our data statistically support the hypothesis that leaving the first egg uncovered serves to provide a more conspicuous bait for potential predators and could be a female tactic for better recognizing predation risk at a nesting site. Thus, if the first uncovered egg is depredated, the female may start a new clutch elsewhere without wasting investment in the clutch at a site under high predation risk.**核心概要**：本领域一项实验支持如下假说：灰山鹑（Grey Partridge，学名*Perdix perdix*）会主动暴露其产下的首枚卵，以此评估其巢址处的捕食风险。 **研究目的**：本研究旨在验证如下假说：雌性灰山鹑会将产下的首枚卵裸露放置，以此评估其选定巢址的捕食风险。 **研究方法**：本研究采用4项独立于研究区域的人工巢实验；以每日巢失败率作为捕食风险的估算指标；统计分析环节采用广义线性混合效应模型（Generalized linear mixed-effects models）。 **研究结果**：研究结果显示，雌性灰山鹑能够预判巢址的安全性：若首枚裸露卵被捕食，则该巢址内整窝卵的捕食风险显著更高。 **研究结论**：本研究数据经统计学分析后，支持如下假说：将首枚卵裸露放置，可作为潜在捕食者更易发现的诱饵，这或是雌性灰山鹑用于精准评估巢址捕食风险的繁殖策略。因此，若首枚裸露卵被捕食，雌性灰山鹑可转而在其他地点重新筑巢产卵，避免在高捕食风险的巢址上浪费繁殖投入。

搜集汇总

背景与挑战

背景概述

该数据集为一项灰山鹑（Perdix perdix）野外实验的原始数据，通过人工巢实验验证雌鸟故意暴露第一枚卵以评估巢址捕食风险的假设。研究结果显示，若第一枚未覆盖卵被捕食，整个巢的捕食风险更高，支持雌鸟利用此行为作为识别风险并优化繁殖投资的策略。