Wintering areas predict age-related breeding phenology in a migratory passerine bird

Understanding connections between breeding, stopover and wintering grounds for long-distance migratory birds can provide important insight into factors influencing demography and the strength of carry-over effects among various periods of the annual cycle. Using previously described, multi-isotope (δ13C, δ15N, δ2H) feather isoscapes for Africa, we identified the most probable wintering areas for house martins (Delichon urbica) breeding at Badajoz in southwestern Spain. We identified two most-probable wintering areas differing in latitude in West Africa. We found that the probability to winter in the northern region was related to age and sex of individuals. Specifically, experienced males (i.e., two years or older) winter in the northern area with a greater probability than experienced females, whereas first-year females winter in the northern area with a greater probability than first-year males. In addition, wintering area was correlated with breeding phenology, with individuals winte...解析长途迁徙鸟类的繁殖地、中途停歇地与越冬地之间的关联，可为理解影响种群动态的因素以及年度周期各阶段间遗留效应（carry-over effects）的强度提供重要见解。本研究借助此前已报道的非洲地区多同位素（δ13C、δ15N、δ2H）羽毛同位素分布图，对在西班牙西南部巴达霍斯繁殖的家毛脚燕（Delichon urbica）的最可能越冬区域进行了识别。研究确定了西非地区两个纬度存在差异的最可能越冬区域。结果显示，在北部区域越冬的概率与个体的年龄和性别相关：具体而言，成年雄鸟（2龄及以上）相较于成年雌鸟，在北部区域越冬的概率更高；而当年幼雌鸟相较于当年幼雄鸟，在北部区域越冬的概率更高。此外，越冬区域与繁殖物候相关，个体越冬