Ecological and physiological convergence in thermoregualtion by Caprimulgid birds and Vespertilionid bats

能量是衡量许多生物功能的成本和收益的货币，很可能是最好地解释动物一般行为，特别是吸热的行为。我的研究项目专注于确定吸温动物如何、何时以及为什么使用“异温”来节省能源的生态背景。日常麻木源于新陈代谢减少，从而降低了体温(TB)，从而节省了能量。使用它的物种数量迅速增加，以及它使吸热动物更不容易灭绝的想法，突显了它的重要性。我们研究了食虫蝙蝠和夜间鸟类(夜壶)对每日麻木的使用，它们的反应在生态和生理上趋同。在短期内，我们将确定麻木使用的广泛模式，长期目标是解决个人在使用麻木时使用麻木的原因，用来启动反应的线索，最后是使用麻木的明显灵活性的原因。可能影响麻木使用的行为和生态因素包括：身体状况、社会互动、觅食成功和栖息地结构。我们对这些因素的相对重要性知之甚少，我们的研究将评估它们之间相互作用的性质。作为对大型棕色蝙蝠的长期研究的一部分，以及最近对银毛蝙蝠的研究成果，我们将测量蝙蝠和鸟类在自然情况下的麻木使用情况，这两个项目都在萨斯喀彻温省的柏树山进行，以及对各种物种的短期研究，包括普通的贫穷遗嘱，南达科他州的惠普-贫穷遗嘱，巴拿马的普通保拉克斯，以及南部非洲有雀斑和红褐色脸颊的夜壶。对于大多数项目，温度敏感型无线电发射器或数据记录器将被用来收集体温数据，作为新陈代谢的指标，以推断自由生活的动物是如何使用麻木的。在可行的情况下，我们将使用心率遥测来更直接地评估自由放养动物的新陈代谢。在可能的情况下，我们将通过实验控制研究动物的食物供应和/或能量成本，以评估哪些因素对刺激麻木使用最重要。我的研究计划最重要的成果将是完善一个与不同动物使用麻木的生态决定因素有关的异温框架。总体而言，我们的结果将使我们能够评估资源可获得性、环境温度、栖息地结构和社会优势等变量对异温所产生的能源节约程度的直接和交互影响，希望能够预测物种和环境，何时麻木将被目前未研究的物种利用。这将加强我们对能源作为一种不断演变的货币的理解。

Energy is the currency by which the costs and benefits of many biological functions are measured and likely best explains behaviour by animals in general and endotherms in particular. My research program is focused on determining the ecological context for how, when and why endotherms use “heterothermy” to save energy. Daily torpor stems from reduced metabolism and thus reduced body temperature (Tb) leading to energetic savings. Its importance is underscored by the rapidly increasing number of species recorded to use it and the idea that it makes endotherms less susceptible to extinction.We study the use of daily torpor by both insectivorous bats and nocturnal birds (nightjars) whose responses converge ecologically and physiologically. In the short-term we will identify broad patterns in torpor use with a long-term goal of addressing why individuals employ it when they do, the cues used to initiate the response, and finally the reasons for the apparent flexibility of its use. Behavioural and ecological factors that likely influence torpor use include: body condition, social interactions, foraging success and roost structure. The relative importance of these factors is poorly understood and our research will assess the nature of interactions between them.We will measure torpor use by bats and birds in natural situations as part of a long-term study of big brown bats and following from recent work on silver-haired bats, both projects taking place in Cypress Hills, Saskatchewan and short-term studies of a variety of species including Common Poorwills, Whip-poor-wills in South Dakota, Common Pauraques in Panama, and Freckled and Rufous-cheeked Nightjars in southern Africa. For most projects, temperature sensitive radio-transmitters or data loggers will be used to collect data on body temperature as a proxy for metabolism to infer how free living animals use torpor. Where feasible we will use heart-rate telemetry to more directly assess the metabolism of free ranging animals. Where possible, we will experimentally manipulate food availability and or the energetic costs incurred by study animals to assess which factors are most important for stimulating torpor use.The most important outcome of my research program will be to refine a Heterothermy Framework relating the ecological determinants of torpor use by diverse animals. Overall our results will allow us to assess both the direct and interactive effects of variables such as resource availability, ambient temperature, roost structure, and social dominance on the degree of energy savings which accrue from heterothermy hopefully to be able to predict both species and circumstances when torpor will be employed by currently unstudied species. This will enhance our understanding of energy as an evolutionary currency.