Data from: Covariation in life-history traits: differential effects of diet on condition, hormones, behavior and reproduction in genetic finch morphs

The relative contribution of genetic and environmental factors in determining variation in life-history traits is of central interest to evolutionary biologists, but the physiological mechanisms underlying these traits are still poorly understood. Here we experimentally demonstrate opposing effects of nutritional stress on immune function, endocrine physiology, parental care and reproduction between red and black head-color morphs of the Gouldian finch (Erythrura gouldiae). Although body condition of black morphs was largely unaffected by diet manipulation, red birds were highly sensitive to dietary changes, exhibiting considerable within-individual changes in condition and immune function. Consequently, nutritionally stressed red birds delayed breeding, produced smaller broods and reared fewer and lower-quality foster offspring than black morphs. Differences in offspring quality were largely due to morph-specific differences in parental effort; red morphs reduced parental provisioning, whereas black morphs adaptively elevated their provisioning effort to meet the increased nutritional demands of their foster brood. Nutritionally stressed genetic morphs also exhibited divergent glucocorticoid responses. Black morphs showed reduced corticosterone-binding globulin (CBG) concentrations and increased levels of free corticosterone, whereas red morphs exhibited reduced free corticosterone levels and elevated CBG concentrations. These opposing glucocorticoid responses highlight intrinsic differences in endocrine sensitivities and plasticity between genetic morphs, which may underlie the morph-specific differences in condition, behavior and reproduction, and thus ultimately contribute to the evolution and maintenance of color polymorphism.

Usage Notes
Pryke et al. Am Nat 52740

在决定生命历史特征变异的遗传和环境因素相对贡献方面，这一直是进化生物学家的核心关注点，但支撑这些特征的生理机制仍然理解不足。本研究通过实验展示了营养压力对红头和黑头金翅雀（Erythrura gouldiae）免疫功能、内分泌生理、亲代抚育和繁殖的相反影响。尽管黑头形态的体况在很大程度上未受饮食操纵的影响，但红鸟对饮食变化极为敏感，表现出显著的个体内条件及免疫功能的改变。因此，营养压力下的红鸟推迟了繁殖时间，产下的幼鸟数量较少且质量较低，抚养的寄养后代数量也较少且质量较差。后代质量的差异主要归因于亲代努力在形态特异性上的差异；红头形态减少了亲代供应，而黑头形态则适应性地提高了供应努力以满足寄养后代的增加营养需求。营养压力下的遗传形态还表现出不同的糖皮质激素反应。黑头形态表现出皮质酮结合球蛋白（CBG）浓度降低和游离皮质酮水平升高，而红头形态则表现出游离皮质酮水平降低和CBG浓度升高。这些相反的糖皮质激素反应突显了遗传形态在内分泌敏感性和可塑性方面的内在差异，这些差异可能导致了形态特异性在条件、行为和繁殖上的差异，从而最终促进了颜色多态性的演化和维持。使用说明

Pryke 等人
《美国自然》第 52740 卷