SEEN - SE European Bird Migration Network
Reversed directions observed while testing nocturnal migrants in orientation cage
Karolina Adamska
Bird Migration Research Station, University of Gdańsk, al. Marszałka Józefa Piłsudskiego 46, 81-378 Gdynia, Poland
e-mail: bioka@univ.gda.pl

The objectives of SEEN organization is to collect scientific data mainly by catching and ringing birds at field stations. One of the standard activities are orientation tests in the Busse’s flat cage, which enable to investigate directional preferences of nocturnal migrants during migration. Testing a lot of  migrants in different places could be a good opportunity to study  a phenomenon of reversed headings, which is quite often observed in cage experiments. Nature of these reversed headings is still not well recognized and seems to be very interesting for further studies. During this analysis data from 26 ringing stations located along the south eastern migration route that leads from Europe (Poland, Latvia, Belarus, Ukraine, Bulgaria) and western Asia (Turkey, Jordan, Palestine, Israel) to northern Africa (Egypt) were used. Five the most frequently caught and tested birds – the Robin (Erithacus rubecula), Blackcap (Sylvia atricapilla), Chiffchaff (Phylloscopus collybita), Willow Warbler (Phylloscopus trochilus) and Reed Warbler (Acrocephalus scirpaceus) were studied. Totally, 19 154 orientation tests were elaborated. Some aspects of birds migration like activity, fat reserves and proportion of young birds as well as their influence on reversed headings were analyzed. Also the geographical position and local topography were taken into consideration.
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