Ecological energetics of small, wild mammals: from flexibility of fitness

半个世纪以来，比较生理学家利用物种比较来了解影响恒温动物（即哺乳动物和鸟类）能量平衡的特征变化的原因。通常，这些比较涉及维持或基础代谢率（BMR），这一特征被认为是重要的，因为它对生殖健康具有重要的直接或间接影响。最近，进化生理学已经认识到研究物种内部和物种之间变异的重要性，这种方法已经成功地应用于哺乳动物冬眠的研究。进化生理学家也开始探讨新陈代谢、生活史特征和行为综合症或动物性格之间的相关性在进化和生态方面的潜在重要性，部分基于这样的预测：在物种内部，“低能量”的行为和生活史特征应该与“低能量”的代谢率相对应。在此背景下，我的目标是：1)确定解释冬眠动物冬眠表达的种内变异的因素；2)检验关于人格、生活史和能量学之间联系的假设；3)开始量化生理和行为性状中表型可塑性对冬眠者的重要性；4)开始将这些表型变异的来源与野生种群的生存和适合度变异联系起来。我和我的学生将对蝙蝠和地松鼠进行实地观察研究和实验室实验，并使用长期数据集将能量和行为特征的种内变化与野外生存和适应性联系起来。这项工作对了解哺乳动物的进化和生态学具有重要意义，对了解物种和种群如何应对环境变化具有重要的应用意义。我们对蝙蝠冬眠的研究对于理解和解决白鼻综合征也很重要，白鼻综合征是一种真菌病原体，自2006年被发现以来，已经导致美国东北部100多万只冬眠的蝙蝠饥饿。

For a half-century, comparative physiologists have used comparisons of species to understand causes of variation in traits affecting energy balance of endotherms (i.e., mammals and birds). Often, these comparisons have addressed maintenance or basal metabolic rate (BMR), a trait thought to be of importance because of significant direct or indirect consequences for reproductive fitness. More recently, evolutionary physiology has recognized the importance of studying variation within, as well as between species and this approach has been applied with particular success to the study of mammalian hibernation. Evolutionary physiologists have also begun to address the potential evolutionary and ecological importance of correlations between metabolism, life history traits and behavioural syndromes or animal personalities based, in part, on the prediction that, within species, "low energy" behavioural and life history traits should correspond with "low energy" metabolic rates. Within this context, I aim to: 1) identify factors which explain intraspecific variation in torpor expression by hibernators; 2) test hypotheses about links between personalities, life histories and energetics; 3) begin to quantify the importance to hibernators of phenotypic plasticity in physiological and behavioural traits; and 4) begin to link these sources of phenotypic variation to variation in survival and fitness in wild populations. My students and I will employ observational field studies and experimental laboratory work on bats and ground squirrels, and use long-term datasets to connect intraspecific variation in energetic and behavioural traits with survival and fitness in the wild. This work has fundamental significance for understanding mammalian evolution and ecology, as well as applied significance for understanding how species and populations might respond to environmental change. Our work on hibernation in bats is also important for understanding and addressing White-Nose Syndrome, a fungal pathogen which has caused starvation of over a million hibernating bats in the northeastern U.S. since its discovery in 2006.