Abstract Diverse spatio-temporal aspects of avian migration rely on relatively rigid endogenous programs. However, flexibility in migratory behavior may allow effective coping with unpredictable variation in ecological conditions that can occur during migration. We aimed at characterizing inter- and intraindividual variation of migratory behavior in a forest-dwelling wader species, the Eurasian woodcock Scolopax rusticola, focusing on spatio-temporal consistency across repeated migration episodes. By satellite-tracking birds from their wintering sites along the Italian peninsula to their breeding areas, we disclosed a remarkable variability in migration distances, with some birds flying more than 6,000 km to Central Asian breeding grounds (up to 101°E). Prebreeding migration was faster and of shorter duration than postbreeding migration. Birds moving over longer distances migrated faster during prebreeding migration, and those breeding at northernmost latitudes left their wintering areas earlier. Moreover, birds making longer migrations departed earlier from their breeding sites. Breeding site fidelity was very high, whereas fidelity to wintering areas increased with age. Migration routes were significantly consistent, both among repeated migration episodes and between pre- and postbreeding migration. Prebreeding migration departure date was not significantly repeatable, whereas arrival date to the breeding areas was highly repeatable. Hence, interindividual variation in migratory behavior of woodcocks was mostly explained by the location of the breeding areas, and spatial consistency was relatively large through the entire annual cycle. Flexibility in prebreeding migration departure date may suggest that environmental effects have a larger influence on temporal than on spatial aspects of migratory behavior.

中文翻译：

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欧亚啄木鸟迁徙行为的个体差异和一致性

摘要 鸟类迁徙的不同时空方面依赖于相对严格的内生程序。然而，迁徙行为的灵活性可能允许有效应对迁徙过程中可能发生的不可预测的生态条件变化。我们旨在表征栖息在森林中的涉禽物种（欧亚鹬 Scolopax rusticola）迁徙行为的个体间和个体间变异，重点关注重复迁徙事件中的时空一致性。通过卫星跟踪鸟类从它们沿着意大利半岛的越冬地到它们的繁殖地，我们发现了迁徙距离的显着变化，一些鸟类飞行超过 6,000 公里到达中亚繁殖地（高达 101°E）。繁殖前迁移比繁殖后迁移更快，持续时间更短。长距离迁徙的鸟类在繁殖前迁徙过程中迁徙速度更快，而在最北纬度繁殖的鸟类则更早离开越冬区。此外，迁徙时间更长的鸟类更早地离开它们的繁殖地。繁殖地的保真度非常高，而越冬地区的保真度随着年龄的增长而增加。迁徙路线在重复迁徙事件之间以及繁殖前和繁殖后迁徙之间都显着一致。繁殖前迁徙出发日期没有显着重复性，而到达繁殖区的日期具有高度重复性。因此，鹧鸪迁徙行为的个体差异主要由繁殖区的位置来解释，并且在整个年循环中空间一致性相对较大。