Data from: A full annual perspective on sex-biased migration timing in long-distance migratory birds

• Main Authors: Briedis, Martins, Bauer, Silke, Adamik, Peter, Alves, José, Costa, Joana, Emmenegger, Tamara, Gustafsson, Lars, Koleček, Jaroslav, Liechti, Felix, Meier, Christoph, Prochazka, Petr, Hahn, Steffen
• Format: Dataset
• Language: unknown
• Published: Dryad Digital Repository 2019
• Subjects: long-distance migrant; Ficedula albicollis; Ficedula hypoleuca; Merops apiaster; Upupa epops; Lanius collurio; annual cycle; sexual selection; Apus apus; Acrocephalus arundinaceus; Ficedula semitorquata; Hirundo rustica; protandry; Cuculus canorus; Coracias garrulus; Tachymarptis melba; Oenanthe oenanthe; Riparia riparia; migration phenology; geolocator; Life sciences; medicine and health care; envir; demo
• Online Access: https://doi.org/10.5061/dryad.t78400r

In many taxa, the most common form of sex-biased migration timing is protandry – the earlier arrival of males at breeding areas. Here we test this concept across the annual cycle of long-distance migratory birds. Using more than 350 migration tracks of small-bodied trans-Saharan migrants, we quantify differences in male and female migration schedules and test for proximate determinants of sex-specific timing. In spring, males on average departed from the African non-breeding sites about 3 days earlier and reached breeding sites ca. 4 days ahead of females. In autumn, males started migration about 2 days earlier, but this difference did not carry-over to arrival at the non-breeding sites. A cross-species comparison revealed large variation in the level of protandry and protogyny across the annual cycle. While we found tight links between individual timing of departure and arrival within each migration season, only for males the timing of spring migration was linked to the timing of previous autumn migration. In conclusion, our results demonstrate that protandry is not exclusively a reproductive strategy but rather occurs year-round and the two main proximate determinants for the magnitude of sex-biased arrival times in autumn and spring are sex-specific differences in departure timing and migration duration. Sex-biased migration timing in 14 Afro-Palearctic migratory birdsdatabase_submission.csv