Nutritional condition of Antarctic Cormorant (Phalacrocorax bransfieldensis) in Nelson Island, South Shetland Islands

BELTRÁN M; BERTELLOTTI M; CASAUX R; D'AMICO VL

Iguazú

Congreso; Ornithological Congress of the Americas; 2017

Blood parameters provide information to monitor the physical condition of wild bird populations. These parameters depend on the intrinsic factors of each species and the environmental conditions at each site. Therefore, they can vary with the diet and consequently with the nutritional condition of individuals, as with the period of reproduction. The Antarctic cormorant (Phalacrocorax bransfieldensis) is a sea bird with extensive biparental care and highly sensitive to the availability of food around breeding sites. The feeding grounds close to the colonies of the Antarctic cormorant located in the South Shetland Islands (ISS) underwent an intense fishing activity which resulted in a decrease in the food supply for cormorants that nest in this archipelago. Throughout the 2016 reproductive cycle at Punta Armonía, Nelson Island (ISS) the nutritional condition of adult cormorants was evaluated by mean of determination of biochemical parameters related to the food ingested (glucose, cholesterol, triglycerides and total proteins). The only parameter that showed a significant intra-seasonal variation was the glucose, decreasing with the advance of the breeding season and with the stage of raising of nestlings. Decrease of glucose could be the result of the immediate energy investment required for parental care of the nestlings therefore, it could be considered that the ISS cormorants maintain a stable nutritional condition throughout the breeding season.