Causes and characteristics of reverse bird migration : An analysis based on radar, radio tracking and ringing at Falsterbo, Sweden
Författare
Summary, in English
That birds migrate in the reverse direction of the expected is a phenomenon of regular occurrence which has been observed at many sites. Here we use three different methods; tracking radar, radiotelemetry and ringing, to characterize the flights of these reverse migrants and investigate possible causes of reverse migration of nocturnally migrating passerines during autumn migration at Falsterbo peninsula, Sweden. Using these different methods we investigated both internal factors, such as age and fuel load, and external factors such as weather variables, competition and predation risk. Birds flying in the reverse direction were more likely to be lean and to be juveniles. Reverse migration was also more common with overcast skies and winds with north and east components. We did not find any effect of temperature, visibility, number of migrating sparrowhawks, or the total number of ringed birds at the site on the day of departure. We found that reverse migration is characterized by slower flight speeds (airspeed) at high altitudes and that it takes place later in the night than forward migration.
Avdelning/ar
Publiceringsår
2016-05-01
Språk
Engelska
Sidor
354-362
Publikation/Tidskrift/Serie
Journal of Avian Biology
Volym
47
Issue
3
Dokumenttyp
Artikel i tidskrift
Förlag
Wiley-Blackwell
Ämne
- Ecology
Status
Published
Forskningsgrupp
- Lund Vision Group
ISBN/ISSN/Övrigt
- ISSN: 0908-8857