Limits to Hummingbird Flight Performance: Ecological and Comparative Perspectives

人们对动物运动表现的限制知之甚少。蜂鸟是飞行过程中增强能量能力的代谢专一化的例证，因此代表了呼吸、心血管和肌肉系统的极端生理设计的主要例子。因此，蜂鸟飞行的分析可能会揭示脊椎动物运动表现的生物力学和生理学的基本限制，包括人类。本研究将研究不同种类蜂鸟飞行性能的限制，并将确定体型、翅膀形态、飞行运动学、空气动力学和呼吸能量学对飞行能力的潜在可变贡献。蜂鸟的种间比较将包括研究跨越海拔梯度的悬停飞行性能，由于空气密度和氧气可用性的物理变化，对飞行动物提出了特殊的空气动力学和生理挑战。通过对蜂鸟在风洞中以不同空速飞行时向前飞行性能的限制进行研究，可以增强悬停飞行的分析。悬停和向前飞行的综合结果将得出关于蜂鸟飞行能力的空气动力学和生理限制的本质的基本结论，并更普遍地描述脊椎动物运动生理学的广泛性能限制。

Limits to exercise performance are little understood in animals. Hummingbirds exemplify metabolic specialization for enhanced energetic capacity during flight, and thus represent a prime example of extreme physiological design in respiratory, cardiovascular, and muscular systems. The analysis of hummingbird flight may thus reveal fundamental limits to the biomechanics and physiology of vertebrate locomotor performance, including that of humans. This study will examine limits to flight performance in diverse hummingbird species, and will determine potentially variable contributions of body size, wing morphology, flight kinematics, aerodynamics, and respiratory energetics to flight capacity. Interspecific comparisons of hummingbirds will include studies of hovering flight performance across altitudinal gradients which, because of physical variation in air density and oxygen availability, present particular aerodynamic and physiological challenges to flying animals. Analysis of hovering flight will be augmented by study of limits to forward flight performance carried out on hummingbirds flying at different airspeeds in a wind tunnel. The combined results for hovering and forward flight will yield basic conclusions as to the nature of aerodynamic and physiological constraints on hummingbird flight capacity, and more generally will delineate broad performance limits to vertebrate exercise physiology.