Airspace is a key but not well-understood habitat for many animal species. Enormous amounts of insects and birds use the airspace to forage, disperse, and migrate. Despite numerous studies on migration, the year-round flight activities of both birds and insects are still poorly studied. We used a 2 year dataset from a vertical-looking radar in Central Europe and developed an iterative hypothesis-testing algorithm to investigate the general temporal pattern of migratory and local movements. We estimated at least 3 million bird and 20 million insect passages over a 1 km transect annually. Most surprisingly, peak non-directional bird movement intensities during summer were of the same magnitude as seasonal directional movement peaks. Birds showed clear peaks in seasonally directional movements during day and night, coinciding well with the main migration period documented in this region. Directional insect movements occurred throughout the year, paralleling non-directional movements. In spring and summer, insect movements were non-directional; in autumn, their movements concentrated toward the southwest, similar to birds. Notably, the nocturnal movements of insects did not appear until April, while directional movements mainly occurred in autumn. This simple monitoring reveals how little we still know about the movement of biomass through airspace.

中文翻译：

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雷达同时记录的高空鸟类和昆虫运动模式的季节性趋势

空域是许多动物物种的关键但却不为人所理解的栖息地。大量昆虫和鸟类利用该空域进行觅食，分散和迁移。尽管有许多关于迁徙的研究，但鸟类和昆虫的全年飞行活动仍很少进行研究。我们使用了来自中欧垂直看雷达的2年数据集，并开发了一种迭代假设检验算法，以研究迁徙和局部运动的一般时间模式。我们估计，在1 km的断面中，每年至少有300万只鸟类和2000万只昆虫通过。最令人惊讶的是，夏季非定向鸟类运动的高峰强度与季节性定向运动高峰的幅度相同。鸟类在白天和晚上的季节性定向运动中显示出明显的峰值，与该地区记录的主要迁徙时期相吻合。昆虫全年发生定向运动，与非定向运动平行。在春季和夏季，昆虫的运动是无方向性的。在秋天，它们的运动集中在西南方向，类似于鸟类。值得注意的是，昆虫的夜间运动直到四月才出现，而定向运动主要发生在秋天。这种简单的监测表明，我们对生物质在空域中的运动知之甚少。昆虫的夜间运动直到四月才出现，而定向运动主要发生在秋天。这种简单的监测表明，我们对生物质在空域中的运动知之甚少。昆虫的夜间运动直到四月才出现，而定向运动主要发生在秋天。这种简单的监测表明，我们对生物质在空域中的运动知之甚少。