Migration Physiology of Birds and Bats

迁徙是动物进行的最具生理要求的活动之一。对于飞行员来说尤其如此，因为飞行能量消耗非常高，飞行时间很长（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加工。将能量和营养分配给移徙可能会损害其他功能，如对疾病或寄生虫的免疫力，相反，免疫或毒性挑战可能会阻碍移徙。因此，迁徙提供了一个很好的模型来研究动物生理性能的限制。我提出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，如何影响鸟类和蝙蝠迁移能力的生理机制和权衡。我的短期目标是：1）在我的实验室建立使用稳定同位素的方法（2）测量高度变化如何影响鸟类的飞行能量学、气体交换、代谢、水平衡和运动学; 3）使用配对的实验室/田间实验来研究饮食、肌肉脂肪酸转运蛋白、疟疾感染、以及汞对鸟类迁徙飞行和中途停留的影响;以及4）检验迁徙蝙蝠在中途停留时栖息期间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用于研究高海拔对飞行和迁移的生物力学和生理学的影响。一个移动的野外实验室和一个大规模自动无线电遥测阵列将用于实验性地操纵候鸟的饮食、肌肉生理、疾病状况和汞负荷，并跟踪它们在安大略西南部40 000平方公里以上的迁徙。我们将使用前沿的分子生物学技术，专门减少鸟类飞行肌肉中关键蛋白的表达，以测试它们对迁移的重要性。该研究计划将培养15 - 20名高素质的人才，推进基础知识，并为保护迁徙物种的实际应用。加拿大大约80%的鸟类迁徙，许多种群正在下降。加拿大的迁徙蝙蝠研究非常少，在风能开发中死亡的风险很高。这项研究将增进我们对这些动物的了解，并提供对重要问题的深入了解，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病的能力，以及汞污染对北方森林的影响。

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.*********