Pre-basic molt, feather quality and modulation of the adrenocortical response to stress in two populations of Rufous-collared sparrows, Zonotrichia capensis

Molt is an energetically expensive process in which birds may allocate 25% or more of their body protein mass to the production of new feathers. Stressful events can interfere with feather growth via the adrenal hormone corticosterone, which is released in response to environmental stress. Corticosterone release, in turn, regulates gluconeogenesis which could directly inhibit protein synthesis and deposition during molt when feathers are growing, which potentially could reduce feather quality dramatically. Thus, many species suppress the adrenocortical stress response, and therefore maintain lower corticosterone levels during molt. In this study we assessed the relationship between plasma corticosterone levels and feather quality in rufous-collared sparrow inhabiting the valleys of the Atacama Desert – one of the most stable and aseasonal environments in the world, and in the semiarid and seasonal Fray Jorge National Park in the north of Chile. We tested two hypotheses; i) feather quali...

换羽（molt）是一项能量消耗极高的生理过程，鸟类在此过程中可将自身25%及以上的体蛋白总量用于新生羽毛的生成。应激事件可通过肾上腺皮质激素皮质酮（corticosterone）干扰羽毛生长——该激素会在机体响应环境应激时释放。而皮质酮的释放又会调控糖异生（gluconeogenesis），该过程可直接抑制换羽期羽毛生长阶段的蛋白质合成与沉积，进而可能大幅降低羽毛质量。因此，诸多鸟类物种会抑制肾上腺皮质应激反应（adrenocortical stress response），从而在换羽期维持较低的皮质酮水平。本研究以栖息于全球最稳定且无明显季节波动的环境之一——阿塔卡马沙漠（Atacama Desert）河谷，以及智利北部半干旱且具季节性特征的弗雷·豪尔赫国家公园（Fray Jorge National Park）内的棕领麻雀（rufous-collared sparrow）为研究对象，探究了血浆皮质酮水平与羽毛质量之间的关联。本研究验证了两项假说：其一，羽毛质量……