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Migration direction in a songbird explained by two loci

Cite this dataset

Sokolovskis, Kristaps et al. (2023). Migration direction in a songbird explained by two loci [Dataset]. Dryad.


Migratory routes and remote wintering quarters in birds are often species and even population specific. It has been known for decades that songbirds mainly migrate solitarily and that the migration direction is genetically controlled. Yet, the underlying genetic mechanisms remain unknown. To investigate the genetic basis of migration direction, we track genotyped willow warblers Phylloscopus trochilus from a migratory divide in Sweden, where South-West migrating and South-East migrating subspecies form a hybrid swarm. We find that migration direction follows a dominant inheritance pattern with epistatic interaction between the two loci explaining 74% of variation. Consequently, most hybrids migrate similarly to one of the parental subspecies and therefore do not suffer from the cost of following an inferior, intermediate route. This has significant implications for understanding the selection processes that maintain narrow migratory divides.


We deployed geolocators across Sweden, retrevied the loggers from the birds that returne3d and used R package geolight to proces raw light data.


Royal Physiographic Society of Lund

Royal Swedish Academy of Sciences

Swedish Research Council, Award: 2017-03937

Danish Ministry of Higher Education and Science, Award: DFF-6108-00597

Swedish Research Council, Award: 2016-05342

National Geographic Society, Award: WW-208R-17