Diversity of the diet and the behavior of Larus dominicanus in the Keller Peninsula, King George Island, South Shetland

DOI: 10.15343/0104-7809.200832.3.5

Abstract

Larus dominicanus has been described as a necrophagous and cleptoparasitic predator. However, in spite of its opportunist
habits, it depends basically on few prey species. Studies done indicate that Larus diet in Antártida is mainly Nacella concinna (Molusca:
Patellidae). Larus dominicanus diet in the Keller Peninsula, King George Island, South Shetlands from February 1996 to February 1997
by means of an analysis of 80 residual pellets and remains left in nests. Forage behavior was registered by direct observation. The allocation
of time of 5 couples with chicks was evaluated during 40 hours of observation distributed in 8 days. Results show that the basic
food of Larus dominicanus in Keller Peninsula is mainly Nacella concinna, anphipoda and fish. The analysis of residual bullets showed
that Nacella concinna was the more important prey of Larus dominicanus (90% of incidence), followed by anphipoda and fish (17.5%
and 15% respectively).