CESIMAR - CENPAT   25625
CENTRO PARA EL ESTUDIO DE SISTEMAS MARINOS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Diet variation in breeding Imperial Cormorants: implications for trophic studies and monitoring
Autor/es:
CRISTIAN MARINAO; NICOLÁS SUÁREZ; CYNTHIA IBARRA; PABLO MARTÍN YORIO
Lugar:
PUERTO IGUAZÚ
Reunión:
Congreso; Ornithological Congress of the Americas/XVII RAO/ XXIV CBO/XCV AFO; 2017
Institución organizadora:
Association of Field Ornithologists, Sociedade Brasileira de Ornitologia y Aves Argentinas
Resumen:
Differences in diet composition were assessed between Imperial Cormorants (Phalacrocorax atriceps) breeding at Isla Arce and Isla Vernacci Este, Golfo San Jorge, Argentina. Both colonies are located within the Patagonia Austral Marine Park and important commercial trawl fisheries operate in adjacent waters, thus knowledge of their food requirement is fundamental to assess potential conflicts and monitor interactions. Induced regurgitations were obtained from 63 breeding adults, 32 at Isla Arce and 31 at Isla Vernacci Este, during two stages of their chick rearing period in the breeding season 2014. A total of 27 prey taxa were recorded in stomach samples at Isla Arce and 30 at Isla Vernacci Este, and at least 21 were common to both islands. Significant differences in diet composition in terms of importance by mass were found between colonies. In addition, significant differences were found between the young and old chick stages at Isla Arce but not at Isla Vernacci Este. Imperial Cormorants consumed benthic, demersal and pelagic prey confirming their plasticity in feeding habits, but their contribution differed depending on the site and chick stage. Results suggest that diet assessments and monitoring of the potential interaction between Imperial Cormorants and fisheries cannot be based on information from a single breeding stage or location, but requires the analysis of diet composition throughout the breeding cycle at a representative sample of the 17 colonies within the marine park.