The relationship between female brooding and male nestling provisioning: does climate underlie geographic variation in sex roles?

Comparative studies of populations occupying different environments can provide insights into the ecological conditions affecting differences in parental strategies, including the relative contributions of males and females. Male and female parental strategies reflect the interplay between ecological conditions, the contributions of the social mate, and the needs of offspring. Climate is expected to underlie geographic variation in incubation and brooding behavior, and can thereby affect both the absolute and relative contributions of each sex to other aspects of parental care such as offspring provisioning. However, geographic variation in brooding behavior has received much less attention than variation in incubation attentiveness or provisioning rates. We compared parental behavior during the nestling period in populations of orange-crowned warblers (Oreothlypis celata) near the northern (64°N) and southern (33°N) boundaries of the breeding range. In Alaska, we found that males were ...对栖息于不同环境的种群开展比较研究，可为解析影响亲代抚育策略差异的生态条件提供关键见解，其中涵盖雄性与雌性的相对投入水平。雄性与雌性的亲代抚育策略，反映了生态条件、社会性配偶的投入以及子代需求三者间的相互作用。气候被认为是鸟类孵卵与育雏行为地理变异的核心驱动因素，进而可影响雌雄两性在亲代抚育其他环节（如子代喂食）中的绝对与相对投入程度。然而，相较于孵卵关注度或喂食频率的地理变异，育雏行为的地理差异迄今尚未得到足够关注。我们针对繁殖分布范围北界（北纬64°）与南界（北纬33°）附近的橙顶虫森莺（Orange-crowned Warbler，Oreothlypis celata）种群，比较了其在雏鸟期的亲代行为。在阿拉斯加，我们发现雄性……