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.

研究观察到，为应对环境变化，诸多物种正改变其迁徙行为。然而鲜有研究能够明确，此类行为改变究竟源于遗传性状、表型可塑性还是灵活适应性调整。本研究报道了一项独特观测结果：大陆黑尾塍鹬指名亚种（Limosa limosa limosa）的种群迁徙路线发生了快速位移——从西班牙偏移至超过300公里外的葡萄牙境内。此次路线偏移并非由成鸟更换中途停歇地导致，因成鸟对停歇地的使用具有高度一致性。实际上，该偏移源于幼鸟主要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，这表明该路线偏移源于发育可塑性而非自然选择。因此，本研究结果表明，全新的迁徙路线可在单一代际内形成，而幼体可能正是这类快速变化的推动者。