Data from: Adaptive strategies in nocturnally migrating insects and songbirds: contrasting responses to wind

1. Animals that use flight as their mode of transportation must cope with
the fact that their migration and orientation performance is strongly
affected by the flow of the medium they are moving in, i.e. by the winds.
Different strategies can be used to mitigate the negative effects and
benefit from the positive effects of a moving flow. The strategies an
animal can use will be constrained by the relationship between the speed
of the flow and the speed of the animal's own propulsion in relation
to the surrounding air. 2. Here we analyse entomological and
ornithological radar data from north-western Europe to investigate how two
different nocturnal migrant taxa, the noctuid moth Autographa gamma and
songbirds, deal with wind by analysing variation in resulting flight
directions in relation to the wind-dependent angle between the
animal's heading and track direction. 3. Our results, from fixed
locations along the migratory journey, reveal different global strategies
used by moths and songbirds during their migratory journeys. As expected,
nocturnally migrating moths experienced a greater degree of wind drift
than nocturnally migrating songbirds, but both groups were more affected
by wind in autumn than in spring. 4. The songbirds’ strategies involve
elements of both drift and compensation, providing some benefits from wind
in combination with destination and time control. In contrast, moths
expose themselves to a significantly higher degree of drift in order to
obtain strong wind assistance, surpassing the songbirds in mean ground
speed, at the cost of a comparatively lower spatiotemporal migratory
precision. 5. Moths and songbirds show contrasting but adaptive responses
to migrating through a moving flow, which are fine-tuned to the respective
flight capabilities of each group in relation to the wind currents they
travel within.

1. 以飞行为移动方式的动物，其迁徙与定向表现会显著受其运动介质的流动（即风力）影响，因此必须应对这一约束条件。可通过多种策略缓解气流带来的负面影响，并利用其正向增益。但动物可采用的策略，将受到气流速度与动物自身相对于周围空气的推进速度之间的相对关系所限制。
2. 本研究利用欧洲西北部的昆虫学与鸟类学雷达数据，通过分析最终飞行方向的变化——该变化与动物航向和航迹方向间的风致角度相关——，探究两类不同的夜行性迁徙类群：夜蛾科银纹夜蛾（Autographa gamma）与鸣禽如何应对风力作用。
3. 本研究基于迁徙沿途固定观测点位的数据，揭示了蛾类与鸣禽在迁徙过程中所采用的差异化全局策略。正如预期，夜行性迁徙的蛾类比夜行性迁徙的鸣禽受到更多风飘移影响，但相较于春季，秋季的两类动物均受风力影响更为显著。
4. 鸣禽的迁徙策略兼具风飘移与航向补偿的双重特征，可在兼顾目的地管控与时间规划的前提下，从气流中获取一定增益。与之形成鲜明对比的是，蛾类为获得强劲的风力助推，会承受显著更高程度的风飘移，其平均地速超过鸣禽，但代价是时空迁徙精度相对更低。
5. 蛾类与鸣禽对气流环境下的迁徙展现出截然不同但均具适应性的响应策略，这些策略会根据各自的飞行能力，并结合其所途经的风场环境进行精细化调整。