Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany.
Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany.
Elife. 2024 Nov 8;12:RP87668. doi: 10.7554/eLife.87668.
Advances in tracking technologies have revealed the diverse migration patterns of birds, which are critical for range mapping and population estimation. Population trends are usually estimated in breeding ranges where birds remain stationary, but for species that breed in remote areas like the Arctic, these trends are often assessed in over-wintering ranges. Assessing population trends during the wintering season is challenging due to the extensive movements of birds in these ranges, which requires a deep understanding of the movement dynamics. However, these movements remain understudied, particularly in the mid-latitudes, where many Arctic breeders overwinter, increasing uncertainty in their ranges and numbers. Here, we show that the Arctic breeding raptor Rough-legged buzzard, which overwinters in the mid-latitudes, has a specific wintering strategy. After migrating ca. 1500 km from the Arctic to mid-latitudes, the birds continue to move throughout the entire over-wintering period, traveling another 1000 km southwest and then back northeast as the snowline advances. This continuous movement makes their wintering range dynamic throughout the season. In essence, this movement represents an extension of the quick migration process, albeit at a slower pace, and we have termed this migration pattern 'foxtrot migration', drawing an analogy to the alternating fast and slow movements of the foxtrot dance. These results highlight the potential errors in range mapping from single mid-winter surveys and emphasize the importance of this migration pattern in assessing the conservation status of bird species. Understanding this migration pattern could help to correctly estimate bird populations in over-wintering ranges, which is especially important for species that nest in hard-to-reach regions such as the Arctic.
追踪技术的进步揭示了鸟类多样的迁徙模式，这对于范围测绘和种群估计至关重要。种群趋势通常在鸟类保持静止的繁殖范围内进行估计，但对于在北极等偏远地区繁殖的物种，这些趋势通常在越冬范围内进行评估。由于这些范围内鸟类的广泛移动，评估冬季的种群趋势具有挑战性，这需要对运动动态有深入的了解。然而，这些运动仍然研究不足，特别是在中纬度地区，许多北极繁殖者在那里越冬，这增加了它们范围和数量的不确定性。在这里，我们展示了北极繁殖猛禽环斑猛禽，它们在中纬度地区越冬，有一种特定的越冬策略。在从北极迁徙约 1500 公里到中纬度地区后，鸟类在整个越冬期间继续移动，再向南西移动 1000 公里，然后随着雪线的推进再返回东北。这种持续的运动使它们的越冬范围在整个季节都具有动态性。本质上，这种运动代表了快速迁徙过程的延伸，尽管速度较慢，我们将这种迁徙模式称为“狐步舞迁徙”，这是对狐步舞中快速和缓慢交替运动的类比。这些结果强调了从单次冬季中期调查中进行范围测绘的潜在误差，并强调了这种迁徙模式在评估鸟类物种保护状况方面的重要性。了解这种迁徙模式有助于正确估计越冬范围内的鸟类种群，这对于在北极等难以到达的地区筑巢的物种尤其重要。
