Data from: Generational shift in spring staging site use by a long-distance migratory bird

In response to environmental change, species have been observed altering their migratory behaviours. Few studies, however, have been able to determine whether these alterations resulted from inherited, plastic, or flexible changes. Here we present a unique observation of a rapid population-level shift in migratory routes — over 300 km from Spain to Portugal — by continental black-tailed godwits Limosa limosa limosa. This shift did not result from adult godwits changing staging sites, as adult site use was highly consistent. Rather, the shift resulted from young godwits predominantly using Portugal over Spain. We found no differences in reproductive success or survival among individuals using either staging site, indicating that the shift resulted from developmental plasticity rather than natural selection. Our results therefore suggest that new migratory routes can develop within a generation and that young individuals may be the agents of such rapid changes.

已有观测表明，物种会响应环境变化而调整其迁徙行为。然而，鲜有研究能够明确此类行为改变究竟源于遗传继承、表型可塑性还是灵活适应性调整。本研究报告了一项独特观测：大陆种群的黑尾塍鹬指名亚种（Limosa limosa limosa）发生了种群尺度上的快速迁徙路线偏移，其路线从西班牙偏移至葡萄牙，偏移距离超过300公里。此次路线转变并非由成鸟更换停歇地所致，因为成鸟对停歇地的使用具有高度一致性。相反，该偏移源于幼鸟更倾向于选择葡萄牙而非西班牙作为停歇地。我们未发现使用两类停歇地的个体在繁殖成功率或存活率上存在差异，这表明此次路线偏移是由发育可塑性驱动，而非自然选择的结果。综上，本研究结果提示，全新的迁徙路线可在单一代际内形成，而幼体或为这类快速变化的主导推动者。