DIETA DEL CORMORÁN GRIS (PHALACROCORAX GAIMARDI) EN LA RÍA DESEADO, SANTA CRUZ, ARGENTINA

ANA MILLONES, ESTEBAN FRERE, & PATRICIA GANDINI

ORNITOLOGIA NEOTROPICAL

Neotropical Ornithological Society

Año: 2005 vol. 16 p. 519 - 527

1075-4377

The aim of this work was to study the diet of the Red-legged Cor-morant (Phalacrocorax gaimardi) on the coast of Argentina. Ninety five pellets were collected at the RíaDeseado, Santa Cruz, between 2002 and 2004. Diet was composed by at least 16 different types of preys,which were arranged into five taxa: fishes, mollusks, crustaceans, polichaetes and algaes. Fishes were themost frequent prey: Patagonotothen spp. (P. Sima, P. cornucola, P. tesellata and P. canina) during the non breedingseason and the sardines Sprattus fuegensis and Ramnogaster arcuata during the breeding season. Benthic algaeswere other important alimentary item during the breeding season, with more than 80% of presence in thepellets. The results showed that the diet of the Red-legged Cormorant is diverse, being composed mainlyby benthic species, which is consistent with the diving behavior of this bird. Nevertheless, the frequency ofoccurrence of meso-pelagic prey was important, being present in almost the half of the samples. The sea-sonal changes registered in the occurrence of some of the prey and the shortage of dominant preys in thedifferent periods of the year suggest an opportunistic feeding behavior in this cormorant.