ABSTRACT The availability of detailed information that encompasses the geographic range of a species, spans a long-term temporal range, and yields individual information (e.g., age and sex), is a principle challenge in ecology. To this end, the North American Bird Banding Laboratory maintains a unique and underutilized dataset that can be used to address core questions of phenological change in migratory birds. We used records from 1966 to 2015 to quantify how the timing of migration has shifted in a long-distance migrant, the Black-throated Blue Warbler (Setophaga caerulescens). Additionally, we examined age and sex differences in the timing of migratory movements. We observed that early spring migrants passed through sites ∼1.1 days earlier per decade and the peak of spring migration also occurred earlier over the 50 yr of this study. Additionally, phenological change was more rapid with increasing latitude during peak spring migratory periods. During fall, the peak of migration stayed consistent across the 50 yr studied, but the migratory season showed protraction overall. During spring, males consistently migrated earlier than females and adults migrated earlier than young individuals. During fall, there was no difference in timing between males and females, but young birds migrated earlier than adults. Additionally, migration proceeded faster in spring compared with the fall. This study reveals differential strategies in migrant timing, across seasons, age groups, and by sex, and shows that en route adjustments across latitude may account for changes in migrant timing. This basic information about such a fundamental ecological process is crucial to our understanding of migration and we must utilize these unique data to appreciate critical shifts at relevant scales of migration.

中文翻译：

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黑喉蓝莺 50 年来迁徙物候的季节性特定变化

摘要 包含物种地理范围、跨越长期时间范围并产生个体信息（例如年龄和性别）的详细信息的可用性是生态学中的主要挑战。为此，北美鸟类带状实验室维护了一个独特且未充分利用的数据集，可用于解决候鸟物候变化的核心问题。我们使用 1966 年至 2015 年的记录来量化长距离迁徙黑喉蓝莺 (Setophaga caerulescens) 迁徙时间的变化。此外，我们检查了迁徙时间的年龄和性别差异。我们观察到，早春移民每十年提前约 1.1 天通过站点，并且在本研究的 50 年中，春季迁徙高峰也发生得更早。此外，在春季迁徙高峰期，随着纬度的增加，物候变化更加迅速。在秋季，整个 50 年的研究中迁徙高峰保持一致，但迁徙季节总体呈延长趋势。在春季，雄性总是比雌性早迁徙，成体比年轻个体迁徙早。在秋季，雄性和雌性之间的时间没有差异，但幼鸟比成年鸟更早迁徙。此外，与秋季相比，春季迁移进行得更快。这项研究揭示了移民时间、跨季节、年龄组和性别的不同策略，并表明跨纬度的途中调整可能解释了移民时间的变化。