Migration is a fundamental ecological phenomenon, which in the Northern Hemisphere involves directed movements between northern breeding grounds and southern non‐breeding grounds. Migratory movements in the opposite direction to the prevailing seasonal routes had been seldom studied and are considered to be an exceptional behavior of animals. Here we present novel insights on avian movement and challenge the traditional perspective of avian migration, by revealing an exceptional movement pattern. We combine analyses of a large dataset based on high‐frequency GPS animal tracking data, deployed on the breeding population of the Judean long‐legged buzzard Buteo rufinus (LLB), along with analyses of remotely sensed data (of a satellite‐based greenness index NDVI – normalized difference vegetation index) to reveal the migratory patterns of this population. This species had never been tagged before and its annual movements were previously unknown. We show that the Judean LLB population is migratory rather than sedentary, and that this population performs a poleward non‐breeding migration from their southern breeding grounds in Israel to their northern non‐breeding grounds in Syria, Turkey and Russia. We suggest that this unusual phenomenon is likely related to food availability in their breeding and non‐breeding grounds. We provide support to the hypothesis that LLBs occupy rich environments, track specific ecological productivity levels along latitude gradients, and maintain consistently lower NDVI levels across their annual cycle compared to NDVI values available in their respective home range. These low NDVI levels are linked to the foraging ecology of LLBs, which forage in relatively open areas characterized by low vegetation. To the best of our knowledge, we present here a most extreme departure from the seasonally appropriate migratory direction of most avian species, by showing a significant poleward non‐breeding pattern and by providing a possible suggestion for this behavior.

中文翻译：

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繁殖种群的无性非移徙：挑战传统的鸟类迁徙观点

迁移是一种基本的生态现象，在北半球涉及北部繁殖地与南部非繁殖地之间的定向运动。很少研究与流行季节路线相反的迁徙运动，这被认为是动物的一种特殊行为。在这里，我们通过揭示一种特殊的运动方式，对鸟类运动提出了新颖的见解，并挑战了传统的鸟类迁徙观点。我们结合基于高频GPS动物跟踪数据的大型数据集的分析，将其部署在Judean长腿秃鹰Buteo rufinus的繁殖种群上（LLB），以及对遥感数据（基于卫星的绿度指数NDVI –归一化差异植被指数）的分析，揭示了该种群的迁徙方式。该物种以前从未被标记过，其年度运动以前未知。我们表明，犹太人的低出生人口是迁徙性的，而不是久坐的，并且该人口从以色列南部的繁殖地向叙利亚，土耳其和俄罗斯的北部非繁殖地进行极向性的非繁殖迁移。我们建议这种异常现象很可能与它们的繁殖和非繁殖场所的食物供应有关。我们支持以下假设：LLB占据着丰富的环境，沿着纬度梯度跟踪特定的生态生产力水平，与各自家庭范围内的NDVI值相比，在整个年度周期内始终保持较低的NDVI水平。这些低NDVI水平与LLB的觅食生态有关，后者在以植被不足为特征的相对开放的地区觅食。据我们所知，在这里我们表现出与大多数鸟类的季节性迁徙方向最极端的偏离，表现出明显的极地非繁殖模式，并为这种行为提供了可能的建议。