Diet composition and prey size of the Great Cormorant (Phalacrocorax carbo sinensis) wintering in rivers and gravel pits of central Spain

Full article

Published:

Volume 42(2), December 1995. Pages 125-131.

Language:

Spanish

Original title:

Composicion de la dieta y tamaño de presa del Cormoran Grande (Phalacrocorax carbo sinensis) durante su invernada en ríos y graveras del centro de España

Keywords:

Central Spain, diet, Great Cormorant, Phalacrocorax carbo sinensis, prey size, wintering.

Abstract:

Diet and prey size of Great Cormorants Phalacrocorax carbo sinensis overwintering in the SE of the Madrid province (central Spain) were studied through pellet analysis and identification of prey remains collected at a communal roosting site. Carps Cyprinus carpio were the main prey in pellets, with 64.7% in number of prey and 64.5% in occurrence frequency. The mean number of fish-prey per pellet was 1.3+0.1 (SE). Carps accounted for 87.0% of the entire and semidigested regurgitated fishes. Other less common prey were Ictalurus melas, Barbus spp., as well as carrion of domestic fowl, Gallus gallus. The average prey size was 132.7+4.5 mm (n = 74). Results are discussed with respect to pellet production and daily food consumption in a recently settled and increasing wintering population of cormorants.