Dissertation Research: The Endocrine Basis of Species Differences in Avian Paternal Care

令人惊讶的是，人们对鸟类父母照料中物种差异的荷尔蒙基础知之甚少。特别令人感兴趣的是，父母的雄性如何将歌唱和领地行为与父母的行为结合起来，因为花在一项活动上的时间通常会排除花在另一项活动上的时间。这项研究的目的是确定荷尔蒙睾酮和催乳素的循环水平是否与两种近缘鸣禽--蓝头青鸟(BHV)和红眼青鸟(REV)--父亲行为的不同有关。雄性BHV孵化卵，而雄性鸣禽则更典型，因为它们不孵卵。因此，这两个物种在雄性对父母照顾的贡献程度上存在很大差异。通过对这两个物种自由生活的雄性进行荷尔蒙调节，这项研究将测试个体循环荷尔蒙水平的变化是否会导致其歌声和父母行为的相应变化。雀形目鸟类是鸟类中最大的一目，其父母照顾的机制还没有像其他鸟类目中的那样受到密切的研究。这项拟议的研究对双亲男性体内睾酮和催乳素的预测功能进行了强有力的测试。

Surprisingly little is known about the hormonal basis of species differences in avian parental care. Of particular interest is how parental males integrate song and territorial behavior with parental behavior, since time spent on one activity usually precludes time spent on the other. The objective of the proposed research is to determine whether circulating levels of the hormones testosterone and prolactin are responsible for the difference in paternal behaviors of two related species of songbird, the blue-headed vireo (BHV) and the red-eyed vireo (REV). Male BHVs incubate eggs, while male REVs are far more typical among songbirds in that they do not. Thus the species differ greatly in the degree to which males contribute to parental care. Using hormone manipulations in free-living males of both species, this research will test whether alterations in an individual's circulating hormone levels will lead to corresponding alterations in its song and parental behaviors. The mechanisms of parental care in Passeriformes, the largest order of birds, have not been examined as closely as those in other avian orders. The proposed research provides a strong test of the predicted functions of testosterone and prolactin in parental males.