International Research Fellowship Program: Effects of Water Balance and Body Size on Thermoregulation in Australian Amphibians

Tracy国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持克里斯托弗·R·特雷西博士与澳大利亚达尔文市北领地大学的基思·A·克里斯蒂安博士合作的为期24个月的研究奖学金。该项目涉及探索温度调节、相互竞争的蒸发冷却过程和身体大小之间的关系，这些物种是海蛙科中与之密切相关的10种澳大利亚青蛙，已知它们的蒸发失水率和身体大小范围很大。为此，他们将开发一个生物物理模型，利用青蛙的物理和生理特性(失水率、表面积、体重、颜色)和气候条件(相对湿度、太阳辐射、环境温度)来确定身体大小和蒸发失水率(EWL)的什么组合可以使青蛙有效地调节体温。然后，他们将测量每种青蛙在一系列与环境相关的温度下的EWL和表现(冲刺速度、跳跃距离)。然后将在实验室测量温度选择，以确定每个物种是否选择了较窄的温度范围，这是体温调节的指示。他们还将使用无线电遥测(较大的物种)来测量体温和野外行为，并直接进行观察和测量，以确定野蛙是否真的将温度调节到一个狭窄的范围。然后，他们将确定EWL、体型和物种选择温度的精确度之间是否存在关系，并预测这些EWL较低、体型较小的物种将能够更好地调节温度，因此选择较窄的范围。了解青蛙与环境相互作用的物理和生理限制，将有助于深入了解人类栖息地改变对青蛙物种的潜在影响。它将帮助我们了解哪些物种更容易因为栖息地的变化而灭绝，比如森林砍伐、城市化甚至全球气候变化。克里斯蒂安在温度调节方面有着悠久的研究历史，在温度调节研究中涉及的重要科学问题的技术和广泛的知识方面拥有深厚的专业知识。

TracyThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four month research fellowship by Dr. Christopher R. Tracy to work with Dr. Keith A. Christian at Northern Territory University in Darwin, Australia.This project involves the exploration of the relationship between thermoregulation, the competing process of evaporative cooling, and body size in 10 closely related Australian frog species (in family Hylidae) that are known to have a wide range of evaporative water loss rates and body sizes. To do this, they will develop a biophysical model that uses physical and physiological properties of frogs (water loss rates, surface area, body mass, color) and climate conditions (relative humidity, solar radiation, ambient temperature) to determine what combinations of body size and evaporative water loss (EWL) rates allow frogs to thermoregulate effectively. They will then measure EWL and performance (sprint speed, hopping distance) for each species of frog across a range of environmentally relevant temperatures. Temperature selection will then be measured in the lab to determine whether each species selects a narrow range of temperatures, an indication of thermoregulation. They will also measure body temperatures and behaviors in the field using radio telemetry (larger species) and direct observations and measurements to determine whether wild frogs actually regulate temperature to a narrow range. They will then determine whether there is a relationship between EWL, body size and the precision with which a species selects temperature, with the prediction that these species with lower EWL and smaller body sizes will be better able to regulate temperatures, and therefore select a narrower range. Understanding the physical and physiological constraints on how frogs interact with their environment will lend insights into the potential impacts of human habitat modification on frog species. It will help us understand which species are more susceptible to extinction due to habitat modifications like deforestation, urbanization or even global climate change.Dr. Christian has a long history of research on temperature regulation and a great depth of expertise in the techniques and extensive knowledge of the important scientific questions involved in the study of thermoregulation.