Unusual occurrence of Illex argentinus (Cephalopoda: Ommastrephidae) in the diet of albatrosses breeding at Bird Island, South Georgia
In Southwest Atlantic waters, the short-finned squid Illex argentinus is distributed along the Patagonian shelf and slope, from approximately 22° to 54°S ( Haimovici et al., 1998). I. argentinus has rarely been recorded in the diet of marine predators breeding on the Falkland Islands, but very few detailed studies have been undertaken (Thompson, 1992). However, it is present in the diet of wandering albatrosses Diomedea exulans (Rodhouse et al., 1987) and white-chinned petrels Procellaria aequinoctialis (Berrow and Croxall, 1999) breeding at Bird Island, South Georgia (54°S 38°W), approximately 600 km distant to the east.
Other predators at South Georgia, such as the grey-headed albatross Thalassarche chrysostoma and black-browed albatross Thalassarche melanophrys have not been recorded
feeding on I. argentinus. The squid component of the diet f those species at South Georgia is dominated by Martialia hyadesi both in number and mass (Rodhouse et al., 1990; Rodhouse and Prince, 1993). This study presents new data on the unusual occurrence of I. argentinus in the diet of
albatrosses breeding at South Georgia in 1999 and evaluates alternative hypotheses to
Authors: Xavier, José C. ORCID record for José C. Xavier, Rodhouse, Paul G., Croxall, John P.