Institute of Marine Research (IMAR/CMA), Department of Life Sciences, University of Coimbra, 3004-517 Coimbra, Portugal.
Zoology (Jena). 2010 Jan;113(1):47-56. doi: 10.1016/j.zool.2009.05.003. Epub 2010 Jan 8.
Flight dynamics theories are influenced by two major topics: how birds adapt their flight to cope with heterogeneous habitats, and whether birds plan to use the wind field or simply experience it. The aim of this study was to understand the flight dynamics of free-flying Cory's shearwaters in relation to the wind characteristics on the coastal upwelling region of continental Portugal. We deployed recently miniaturised devices-global positioning system loggers to collect precise and detailed information on birds' positions and motions. Prevalent winds were blowing from the north-east and adults used those winds by adjusting their flight directions mainly towards north-west and south-west, flying with cross and tail winds, respectively, and avoiding head winds. This is confirmation that Cory's shearwaters use a shear soaring flying strategy while exploiting the environment for food: adults foraged mainly with cross winds and their ground speed was not constant during all foraging trips as it changed dynamically as a result of the ocean surface shear winds. During travelling phases, ground speed was strongly influenced by the position of the bird with regard to the wind direction, as ground speed increased significantly with increasing tail wind component (TWC) values. Adults appear to choose foraging directions to exploit ambient wind, in order to improve shear soaring efficiency (cross winding) and exploit diurnal changes in tail wind strength to maximise commuting efficiency. We report, for the first time, precise ground speed values (GPS-derived data) and computed actual flight speed values (using TWC analysis) for Cory's shearwater.
鸟类如何适应其飞行以应对异质生境，以及鸟类是否计划利用风场或只是体验风场。本研究旨在了解游离飞行的黑眉信天翁在葡萄牙大陆沿海上升流区与风特征有关的飞行动力学。我们部署了最近的微型设备-全球定位系统记录器，以收集关于鸟类位置和运动的精确和详细信息。盛行风从东北吹来，成年鸟通过调整飞行方向主要向西北和西南方向飞行，分别顺风和逆风飞行，并避开顶风。这证实了黑眉信天翁在利用环境觅食时使用剪式翱翔的飞行策略：成年鸟主要在顺风中觅食，并且它们的地面速度在所有觅食过程中并不恒定，因为它会随着海面剪风的变化而动态变化。在飞行阶段，地面速度受到鸟类相对于风向位置的强烈影响，因为随着顺风分量（TWC）值的增加，地面速度显著增加。成年鸟似乎选择觅食方向来利用环境风，以提高剪式翱翔效率（顺风）并利用尾风强度的昼夜变化来最大化通勤效率。我们首次报告了黑眉信天翁的精确地面速度值（GPS 衍生数据）和计算的实际飞行速度值（使用 TWC 分析）。
