Resumen

PETRACCI, Pablo F.; DELHEY, Kaspar  y  SOTELO, Martín. Granivorous habit in Olrog's Gull (Larus atlanticus): implications for its specialist status. Hornero [online]. 2007, vol.22, n.1, pp. 51-54. ISSN 1850-4884.

We report on unknown feeding habits of the Olrog's Gull (Larus atlanticus) in the area of Ingeniero White port, Bahía Blanca, Buenos Aires Province, Argentina. Between 2002 and 2005, 281 individuals were observed feeding on grains along the shoulder of the road and in a parking lot besides the port. Feeding groups were of 2-51 individuals. This behaviour was observed mostly (78%) during high tides, when access to intertidal prey is limited. The exploitation of human resources by Larus atlanticus supports the hypothesis that this species has some degree of trophic plasticity and could behave as a generalist. We briefly review the literature on its diet, proposing an explanation for the different observations obtained along the coast of Argentina.

Palabras llave : Argentina; Bahía Blanca; diet; grains; Larus atlanticus; Olrog's Gull.