Migration Physiology of Birds and Bats

迁徙是动物进行的对生理要求最高的活动之一。对于飞行员来说尤其如此，因为飞行能量消耗异常高，航班需要长时间维持(许多小时，但长达9天没有水、食物或休息)，加油需要高水平的活动和营养处理。为迁徙分配能量和营养可能会损害其他功能，如对疾病或寄生虫的免疫力，反过来，免疫或毒性挑战可能会阻碍迁徙。因此，迁徙提供了一个很好的模型来研究动物的生理表现极限。*我提议的研究计划的长期目标是了解环境因素，如大气条件、疾病、污染物和栖息地质量，如何影响控制鸟类和蝙蝠迁徙能力的生理机制和权衡。我的短期目标是：1)在我的实验室建立方法，使用呼吸中的稳定同位素(13C浓缩)来测量飞行中的代谢率和燃料氧化；2)测量海拔变化如何影响鸟类的飞行能量、气体交换、新陈代谢、水分平衡和运动学；3)使用实验室/现场配对实验来研究饮食、肌肉脂肪酸转运体、疟疾感染和汞对鸟类迁徙飞行和中途停留的影响；以及4)验证迁徙蝙蝠在中途停留时栖息时的能量消耗对环境温度不敏感的假设。*我们将使用令人兴奋的新设施和技术来进行拟议的研究。一个专门为鸟类设计的独特的低压气候风洞将被用来研究高海拔对飞行和迁徙的生物力学和生理学的影响。一个流动的野外实验室和一个大规模的自动无线电遥测阵列将被用来实验性地操纵候鸟的饮食、肌肉生理、疾病状态和汞负荷，并跟踪它们在安大略省西南部超过40,000平方公里的迁徙。我们将利用前沿的分子生物学技术，专门降低鸟类飞行肌肉中关键蛋白质的表达，以测试它们对迁徙的重要性。*该研究计划将培养15-20名高素质人员，提高基础知识，并在候鸟物种保护方面具有实际应用。加拿大约80%的鸟类迁徙，许多鸟类的数量正在减少。加拿大的迁徙蝙蝠的研究非常少，而且在风能开发中面临更高的死亡风险。这项研究将提高我们对这些动物的了解，并提供对重要问题的洞察，例如气候变化影响迁徙飞行的可能性，候鸟远距离传播人畜共患疾病的能力，以及北方森林中汞污染的影响。

Migration is one of the most physiologically demanding activities animals perform. This is particularly true for fliers because flight energy expenditure is exceptionally high, flights are maintained for long periods (many hours, but up to 9 days without water, food or rest), and refueling demands high levels of activity and nutrient processing. The allocation of energy and nutrients to migration may impair other functions, such as immunity against diseases or parasites, and conversely, immune or toxic challenges may impede migration. Thus, migration offers an excellent model to study the limits to physiological performance of animals.****The long term objective of my proposed research program is to understand how environmental factors, such as atmospheric conditions, disease, pollutants, and habitat quality, influence the physiological mechanisms and trade-offs that govern the abilities of birds and bats to migrate. My short term objectives are: 1) to establish methods in my lab to use stable isotopes (13C enrichment) in breath to measure metabolic rate and fuel oxidation during flight; 2) to measure how variation in altitude affects flight energetics, gas exchange, metabolism, water balance, and kinematics in birds; 3) to use paired lab/field experiments to study effects of diet, muscle fatty acid transporters, malarial infection, and mercury on migratory flight and stopover in birds; and 4) to test the hypothesis that energy consumption during roosting is insensitive to ambient temperature in migrating bats at stopover.*****We will use exciting new facilities and technologies for the proposed research. A unique hypobaric, climatic wind tunnel, specifically designed for birds, will be used to study the effects of high altitude on the biomechanics and physiology of flight and migration. A mobile field laboratory and a large-scale automated radio-telemetry array will be used to experimentally manipulate the diets, muscle physiology, disease status and mercury burdens of migratory birds, and track their migrations over 40,000 km2 in southwest Ontario. We will use leading-edge molecular biology techniques to specifically reduce the expression of key proteins in bird flight muscles to test their importance for migration.*****The research program will train 15 - 20 highly qualified personnel, advance basic knowledge, and have practical applications for the conservation of migratory species. About 80% of Canada's birds migrate, and many populations are declining. Canada's migratory bats are very poorly studied, and are at elevated risk for mortality at wind energy developments. This research will improve our understanding of these animals, and provide insight into important problems, such as the potential for climate change to affect migratory flight, the ability of migratory birds to spread zoonotic diseases over long distances, and the effects of mercury contamination in boreal forests.*********