Avian Nutritional Ecology

在自由生活的动物中，营养需求随季节而变化，并且必须从数量和质量都不同的食物供应中得到满足。研究这些动物如何（生理的、形态的、行为的）满足供给和需求，或者如何科普短缺的方法，通常被称为“营养生态学”。“这个项目涉及一种典型的杂食性鸟类白冠麻雀的营养生态学的四个方面：（1）小型鸟类通过什么样的代谢和行为反应来减少或容忍营养过剩？急性和慢性腹泻的界限有什么区别？(2)换羽（一个在年周期中代表营养瓶颈的过程）的热量和氨基酸消耗是否随光周期（因此也随纬度）而变化？(3)与其他生产形式（40- 80%）相比，蜕皮的热量效率（5-10%）非常低，是什么原因造成的？(4)换羽的鸟类会把它们的骨骼和羽毛一起更新吗？如果是这样的话，这是否有助于解释换羽的明显的高成本和低效率？这些问题的答案将为更好地理解野生动物不稳定的营养需求提供基础。

Nutritional requirements vary through the seasons in free- living animals, and must be fulfilled from food supplies that also vary in both quantity and quality. The study of the ways (physiological, morphological, behavioral) in which such animals match supply and demand or cope with shortage is often called "nutritional ecology." This project concerns four aspects of the nutritional ecology of an archetypical omnivorous bird, the White-crowned Sparrow: (1) By what metabolic and behavioral responses do small birds minimize or tolerate nutritional privation? What are the differences in the limits of acute and chronic privation? (2) Do the caloric and amino-acid costs of molt (a process representing a nutritional bottleneck in the annual cycle) vary with photoperiod (and hence with latitude)? (3) What accounts for the very low caloric efficiency of molt (5-10%) compared with that of other forms of production (40- 80%)? (4) Do molting birds renovate their skeleton together with their plumage? If so, does this help explain the apparently large cost and low efficiency of molt? The answers to these questions will provide a basis for understanding better the labile nutritional requirements of animals in the wild.