DISSERTATION RESEARCH: The Effects of Ecology and Evolution on Avian Flight Morphology

小岛上的鸟类比它们在大岛屿上的近亲有更小的飞行肌肉和更长的腿。这些差异是如何影响功能的呢？小岛上的鸟类可能遭遇较少的捕食，也不需要迅速起飞。它们能够通过减少飞行肌肉的大小来节省能量，而长腿可以在起飞时弥补肌肉的不足。这可能会导致小岛上的鸟类整体起飞速度较慢。这项研究旨在检验这些关于岛屿人口差异如何影响起飞的假设。将研究特立尼达和多巴哥岛上五种鸟类的起飞机制。一个装有应变计和高速摄像机的栖木将用于测量腿推力产生的力，以及飞行速度、加速度和机翼运动。这些数据将用于计算：(1)腿推力、翼拍和峰值加速度的时机；(2)腿推力产生的总力；(3)腿推力和起跳结束时的速度；(4)腿部对起飞速度的贡献率。本研究旨在评估岛屿进化的功能后果，并测试小岛屿物种在直接影响其竞争和逃避捕食者的能力方面与近亲的功能差异。这些功能性生物力学差异可能有助于解释为什么岛屿物种如此容易受到人类干扰和引进物种的影响。这个项目将包括培养生物学本科生的研究技能。

Birds on small islands have smaller flight muscles and longer legs than their close relatives on larger islands. How do these differences affect function? Birds on small islands might experience less predation, and do not need to take off as rapidly. They are able to save energy by reducing the size of flight muscles, and the longer legs could compensate for smaller muscles during takeoff. This might lead to a slower overall takeoff for birds on small islands. This study aims to test these hypotheses about how differences among island populations affect takeoff. The take-off mechanics of five bird species on the islands of Trinidad and Tobago will be studied. A perch instrumented with strain gauges and a high-speed video camera will be used to measure force generated by the leg thrust as well as flight velocity, acceleration, and wing movements. These data will be used to calculate: (1) the timings of leg thrust, wingbeat, and peak acceleration; (2) total forces produced by the leg thrust; (3) velocities at the end of the leg thrust and of take-off; and (4) percent leg contribution to take-off velocity. This study aims to assess the functional consequences of island evolution and to test how small-island species differ functionally from their close relatives in ways that directly affect their abilities to compete and escape predators. These functional biomechanical differences might help explain why island species are so vulnerable to human disturbance and introduced species. This project will involve training undergraduate biology students in research skills.