Metabolic Rates and Parental Feeding of Male and Female Nestlings

高瓦蒂博士发现，性别会影响照顾它们的成年人（假定为父母）和雏鸟之间的互动：父亲喂养女儿的频率要高于喂养儿子的频率。这是因为女儿比儿子需要更多的能量吗？高瓦蒂博士将验证一个假设，即女儿比儿子需要更多的能量才能长到同样的大小和体重。性别偏见喂养发生在那些已经探索过性别相互作用的鸟类物种中，但这种性别影响的直接原因尚未得到评估。东方蓝知更鸟为有效研究这种影响提供了机会，因为雏鸟（与其他物种不同）可以简单地通过主翼羽毛的颜色来确定性别，而且，通过在巢箱内拍摄，可以很容易地收集到父母和雏鸟如何互动的数据。双标签水法是一种成熟的测量野生动物代谢率的技术。Gowaty博士将使用这项技术来评估在整个雏鸟生活中不同年龄的儿子和女儿的代谢率。如果女儿的代谢率没有比儿子高，那么父亲给女儿比儿子多喂的原因还需要进一步的研究。这个研究项目的发现将是重要的，因为它是第一次尝试测量野生鸟类的儿子和女儿的代谢差异，这些信息对于理解鸟类父母的亲代照顾模式至关重要。无论儿子和女儿的代谢率是否不同，答案将有助于阐明鸟类亲代照顾的原因和控制。

Dr. Gowaty has discovered that gender affects interactions between caregiving adults (presumed parents) and nestling eastern bluebirds: Fathers feed their daughters more often than they feed their sons. Is this because daughters have greater energy requirements than sons? Dr. Gowaty will test the hypothesis that daughters need more energy than do sons to grow to the same size and weight. Gender-biased feeding occurs in those bird species in which gender interactions have been explored, but the proximate causation of such gender effects has not been evaluated. Eastern bluebirds provide an opportunity for efficient study of such effects because nestling bluebirds (unlike other species) can be assigned to gender simply by the color of the primary wing feathers, and because data on how parents and nestlings interact can be readily collected by filming inside a nest box. The doubly-labeled-water method is a well-established technique for measuring metabolic rates of animals living in the wild. Dr. Gowaty will use this technique to evaluate the metabolic rates of sons and daughters at various ages throughout nestling life. If daughters do not have higher metabolic rates than sons, the explanation for why fathers feed their daughters more than their sons will require additional investigation. The findings of this research project will be important, if only because it is the first attempt to measure metabolic differences of sons and daughters of wild-living birds, information that is critical to understanding patterns of parental care by avian parents. Whether or not sons and daughters differ in metabolic rates, the answer will be useful for elucidating the causation and control of parental care in birds.