Deconstructing incubation behaviour in response to ambient temperature over different timescales

Avian embryos need a stable thermal environment to develop optimally, while incubating females need to allocate time to self-maintenance off the nest. In species with female-only incubation, eggs are exposed to ambient temperatures that usually cool them down during female absences. The lower the ambient temperature the sooner females should return to re-warm the eggs. When incubation constraints ease at increasing ambient temperatures, females respond by increasing either incubation effort or self-maintenance time. These responses are population-dependent even within the same species; but it is uncertain whether they are caused by local environmental conditions or they are an artefact from limited datasets, different methodological approaches or the timescale over which incubation behaviour is measured. In this study, we collected incubation data from three Mediterranean Great TitParus major populations during three consecutive years. We measured the duration of each off- and on-bout e...鸟类胚胎需要稳定的热环境以实现最优发育，而参与孵卵的雌性个体则需分配时间离巢开展自我维持行为（如觅食、休憩等）。在仅由雌性承担孵卵任务的物种中，当雌鸟离巢时，卵会暴露于环境温度下，通常会出现降温。环境温度越低，雌鸟越应尽快返回巢中为卵重新加温。当环境温度升高、孵卵约束缓解时，雌鸟会通过增加孵卵投入或延长离巢自我维持时间来做出响应。即便在同一物种内，这些响应也存在种群特异性差异；但目前尚不清楚这些差异是由当地环境条件导致，还是受限于数据集规模、研究方法差异或孵卵行为观测时长所产生的人为误差。本研究中，我们连续三年收集了三个地中海大山雀（Great Tit, *Parus major*）种群的孵卵数据，并记录了每次离巢时段（off-bout）与归巢孵卵时段（on-bout）的时长……