Agnieszka Ożarowska
Bird Migration Research Station, University of Gdańsk, Przebendowo, 84-210
Choczewo, Poland
bioat@univ.gda.pl
The Blackcap (Sylvia atricapilla) is one of the species showing complex
migration system resulting from, among others, high population differentiation.
These populations not only differ in the location of wintering quarters but also in
migration strategy. The species is one of the most common used in orientation
studies as well. All tested birds were caught with mist-nets, ringed and standard
measurements were taken that included also fat-scoring. The blackcaps were
tested in orientation cages following procedures proposed by Busse (1995).
Material was collected during autumn migration season at several ringing
stations: Bukowo (N Poland), Kaliszany (S Poland), Carpatica (S Poland), Arosio
(N Italy), Cernek (N Turkey), Akyatan (S Turkey), Dhleil (Jordan). Different
locations of these stations on the species migration flyways enabled to find some
site specific characteristics of the Blackcap migration strategy. The analysis of
migrational direction distributions at each of these stations showed high
differentiation. At each location at least two main migrational axes could be
determined. The fat score of the individuals showing distinguished migrational
directions was analysed. The fat-score distribution in relation to migrational
direction showed local characteristics of this phenomenon at each location along
the migratory route of the species. The very interesting pattern was found at
Arosio ringing station. This station location is a very special one as it covers both
? wintering grounds of the species as well as a stop-over place for the
populations heading towards African winter quarters. The results showed two
main migrational directions at this station and individuals representing these
directions differed in the fat-score distribution. This could suggest different
migration strategy of the Blackcap populations that winter within this region and
other that are long-distance migrants heading towards African winter quarters.




