Autumn orientation behaviour of paddyfield warblers, Acrocephalus agricola, from a recently expanded breeding range on the western Black Sea coast
Författare
Summary, in English
The paddyfield warbler, Acrocephalus agricola, has extended its breeding range from Central Asia to the western Black Sea coast. The Balkan population offers a unique chance to test the effect of breeding range expansion on the genetically programmed migratory direction. We studied 21 paddyfield warblers at Durankulak Lake, NE Bulgaria, by recording their autumn migratory orientation in circular orientation cages. Our data show that the preferred migratory orientation is directed along a NE-SW axis. Paddyfield warblers seem to avoid direct crossing of the Black Sea by following the western coast. The mean bearing was parallel to the nearest coastline and corresponds to the direction of the historical breeding range expansion of the species. In our experiment many individuals showed south-western orientation in autumn, a course which would potentially lead the birds to exploratory movements outside the current breeding range. An axial orientation response has been often shown in circular cage tests, and can be due to factors such as coastal orientation or reverse orientation triggered by the physiological condition of some individuals. However, it might also be one of the driving mechanisms for range expansion. Hence, we can expect the future expansion of Balkan paddyfield warblers to continue towards south-west. (c) 2010 Elsevier B.V. All rights reserved.
Avdelning/ar
Publiceringsår
2010
Språk
Engelska
Sidor
167-171
Publikation/Tidskrift/Serie
Behavioural Processes
Volym
85
Issue
2
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Biological Sciences
Nyckelord
- migration program
- Genetic
- Detour migration
- Balkan Peninsula
- Breeding range expansion
- Passerine bird
- Topography
Status
Published
Forskningsgrupp
- Animal Navigation Lab
ISBN/ISSN/Övrigt
- ISSN: 0376-6357