Epsilon Open Archive

Abstract

Stopover behaviour is a central element ofmigration strategies. But in recent geolocator studies,despite now being able to track individual songbirdsduring their entire migration, their stopover behaviourhas received little attention. We used light-sensitivegeolocators to identify the migratory routes and schedulesof 12 northern wheatears (Oenanthe oenanthe) breedingin Sweden. Three geolocators collected temperature datacomplementing inferences from light data by providingadditional information on behaviour during migration.The wheatears performed a slow migration withconsiderable stopover time (84%/76% of autumn/springmigration), with short stops while traveling throughEurope, and a prolonged stopover period in both autumnand spring in the Mediterranean region. Spring migrationwas faster than autumn migration, mainly because ofdecreased stopover time. Migration routes and timeschedules were similar to those from a German breedingpopulation. Compared to wheatears breeding in Alaskawith a three-fold migration distance, Swedish wheatearsspent more time during stopovers during autumn andspring migration, suggesting less time constraints andpotential flexibility in migration schedules. The findingof prolonged stopovers, similar to other recent geolocatorstudies, shows that temporary residency periods maybe common. This changes our current view on stopoverecology to one where temporary residency periods arepart of spatio-temporal strategies optimising resource useduring the entire annual cycle.