Diet of the Great Cormorant (Phalacrocorax carbo sinensis) at two areas in the Bay L vstabukten, South Bothnian Sea, Sweden, based on otolith size-correction factors

Abstrakti

The diet of cormorants roosting at Malause on the Garonne River (South- West France) was studied by analyzing pellets collected during the winter 2001- 2002. This roost held a mean of 550 cormorants between October 2001 and March 2002, making it one of the most important winter roosts in France. The diet contained 14 fish species, including 10 cyprinids. Cyprinids were the most abundant prey, representing 90 % of individual fish. Bream Abramis brama between 100 and 150 mm in length were the most abundant food items, while large bream ( >300mm total length) were also consumed. The proportion of pellets containing bream increased from 26 % in October- November to 69% in February- March. There was no significant change in the size of the bream over time. The next most abundant species was pikeperch Sander lucioperca present in 15.4% of the pellets from December- January but only 2.6% in February- March.