Richardson W J
LGL Ltd., King City, Ontario, Canada.
EXS. 1991;60:226-49. doi: 10.1007/978-3-0348-7208-9_11.
Migratory flights are strongly affected by wind, and birds have developed many adaptations to cope with wind effects. By day, overland migrants at high altitudes may often allow crosswinds to drift their tracks laterally from the preferred heading. In contrast, many birds at low altitude adjust their headings to compensate for drift, and may overcompensate to allow for previous drift. The relative motion of landscape features is probably used to sense drift, at least by day. By night, some overland migrants compensate fully for drift, but others do not. Compensation may be more common where there are prominent topographic features. Over the sea, compensation is rarely if ever total; wave patterns may allow partial compensation. Other adaptations can include reduction of drift by flying at times and/or altitudes without strong crosswinds. Some birds recognize the need to change course to allow for previous wind displacement, and reorient at least roughly toward the original route or destination. Some juveniles en route to previously unvisited wintering grounds seem to have this ability, but corroboration is needed. Such reorientation may not require a true navigation ability. However, some birds have unexplained abilities to sense the wind while aloft.
迁徙飞行受到风力的强烈影响，鸟类已经进化出许多适应性特征来应对风力的影响。白天，高空的陆地迁徙鸟类常常会让侧风将它们的飞行轨迹从首选方向横向偏移。相比之下，许多低空飞行的鸟类会调整飞行方向以补偿偏移，并且可能会过度补偿以抵消之前的偏移。至少在白天，景观特征的相对运动可能被用来感知偏移。夜间，一些陆地迁徙鸟类会完全补偿偏移，但其他鸟类则不会。在有显著地形特征的地方，补偿可能更为常见。在海上，补偿很少能达到完全补偿；海浪模式可能允许部分补偿。其他适应性特征包括在没有强侧风的时间和/或高度飞行以减少偏移。一些鸟类意识到需要改变路线以抵消之前的风致位移，并至少大致重新朝向原来的路线或目的地。一些前往此前未去过的越冬地的幼鸟似乎具备这种能力，但仍需证实。这种重新定向可能并不需要真正的导航能力。然而，一些鸟类在空中能够感知风的能力却无法解释。
