SEEN - SE European Bird Migration Network
The Blackcap: short- vs. long-distance migration - advantage vs. disadvantage?
Agnieszka Ożarowska, Grzegorz Zaniewicz
Bird Migration Research Station, University of Gdańsk, al. Marszałka Józefa Piłsudskiego 46, 81-378 Gdynia, Poland

Distinct decline was observed in number of Palearctic trans-Saharan migrants. The Sylvia warblers were one of the group showing the most dramatic changes in last century. While the decline is still observed in birds migrating along the western Palearctic flyway, the long-term studies on the Polish Baltic coast indicated increasing trend in most common warblers: Sylvia atricapilla, Sylvia borin, Sylvia curruca and Sylvia communis from the 90ties of the last century onwards. To find out what are the reasons for the observed difference, the studies on biology/ecology of populations following different migration routes and wintering in different winter African quarters are essential. The network of ringing stations located along the SE flyway (SE European Bird Migration Network) enabled the studies on migrants heading along this route towards wintering quarters in East Africa and comparing them to data from Italy, i.e. the Apennine migration flyway. This study included data from several ringing stations in Russia, Poland, Ukraine, Turkey, Jordan, as well as in Italy. We observed increase in the number of the short-distance migrants in Central/Eastern Europe, which might result from improved conditions at the wintering and breeding grounds of these populations due to global warming. It seems as if short-distance migrants quickly respond to changing environmental conditions by behavioural (?genetic) adaptations, while long-distance migrants are more conservative.
Created by Pronetix 2006