Body mass and fat score changes in recaptured birds during the autumn migration at the Cernek ringing station in Turkey

The fat level and the body mass of recaptured birds ringed at the Cernek Ringing Station are presented in this study. Data from autumns of 2003-2005 were analysed. Species of different migratory and feeding habits are compared. A total of 351 recaptures of the Blackcap (Sylvia atricapilla), Garden Warbler (S. borin), Reed Warbler (Acrocephalus scirpaceus), Marsh Warbler (A. palustris) and Cetti's Warbler (Cettia cetti) were mist-netted and handled according to the South-East European Bird Migration Network (SEEN) standards.

The mean weight changes of the Reed Warbler and Marsh Warbler and those of the Blackcap and Garden Warbler were similar within each genus but higher in Sylvia spp. as compared to Acrocephalus spp. The recapture rate was the highest in the Cetti's Warbler but the mean weight increase was the lowest as this is essentially a sedentary species. The stopover duration differed among the species. The mean stopover length was similar within Acrocephalus spp. (8.5 days in the Reed Warbler, 6.4 days in the Marsh Warbler) and Sylvia spp. (5.6 days in the Blackcap, 5.4 days in the Garden Warbler) and different in the Cetti's Warbler (16.6 days).

Results indicate that migratory birds use Cernek location as refuelling station during the autumn migration and their fat level and body mass increase, but differ according to feeding and migrating habits.