Bégin-Marchand Camille, Desrochers André, Taylor Philip D, Tremblay Junior A, Berrigan Lucas, Frei Barbara, Morales Ana, Mitchell Greg W
Wildlife Research Division, Environment and Climate Change Canada, 1550 d'Estimauville, Québec, QC, G1J 0C3, Canada.
Université Laval, 2325 Rue de l'Université, Québec, QC, G1V 0A6, Canada.
Mov Ecol. 2021 May 13;9(1):23. doi: 10.1186/s40462-021-00263-9.
Migratory connectivity links the different populations across the full cycle and across the species range and may lead to differences in survival among populations. Studies on spatial and temporal migratory connectivity along migration routes are rare, especially for small migratory animals.
We used an automated radio-telemetry array to assess migratory connectivity en route and between early and later stages of the fall migration of the eastern populations of Swainson's Thrush, and to assess the variation of migration pace between consecutive detection from the different receiving stations along the migratory journey. We tracked 241 individuals from across eastern Canada to determine if populations were mixing around the Gulf of Mexico. We also tested the influence of tagging longitude, latitude and age on migration pace.
Migration routes varied and converged towards the northeast coast of the Gulf of Mexico, but in this region, populations maintained finer-scale spatial structure. Migration pace increased as birds progressed south, independent of age and tagging site.
We showed that for songbirds, migratory connectivity can be maintained at fine spatial scales despite the regional convergence of populations, highlighting the importance of detailed spatial tracking for identification of population specific migration routes. Overall, our study provides a portrait of migratory movements of eastern Swainson's Thrush and a framework for understanding spatial structure in migration routes for other species.
迁徙连通性将整个生命周期和物种分布范围内的不同种群联系起来，可能导致种群间生存差异。关于沿迁徙路线的时空迁徙连通性的研究很少，尤其是对于小型迁徙动物。
我们使用自动无线电遥测阵列来评估旅鸫东部种群秋季迁徙途中以及早期和后期之间的迁徙连通性，并评估沿迁徙路线不同接收站连续检测之间迁徙速度的变化。我们追踪了来自加拿大东部各地的241只个体，以确定种群是否在墨西哥湾周围混合。我们还测试了标记经度、纬度和年龄对迁徙速度的影响。
迁徙路线各不相同，且都汇聚于墨西哥湾东北海岸，但在该区域，种群保持着更精细的空间结构。随着鸟类向南迁徙，迁徙速度加快，与年龄和标记地点无关。
我们表明，对于鸣禽来说，尽管种群在区域上汇聚，但迁徙连通性仍可在精细空间尺度上维持，突出了详细空间追踪对于识别特定种群迁徙路线的重要性。总体而言，我们的研究描绘了东部旅鸫的迁徙运动情况，并为理解其他物种迁徙路线的空间结构提供了一个框架。
