Diet of Olrog's Gull (Larus atlanticus) in the Mar Chiquita coastal Lagoon (Buenos Aires, Argentina) during non-breeding period.

作者：Paula Beron Maria; Favero Marco

来源：Ornitologia Neotropical, 2010, 21(2): 215-224.

• Olrog's Gull
• Laws atlanticus
• crabs
• non-breeding diet

Diet of Olrog's Gull (Larus atlanticus) in the Mar Chiquita coastal Lagoon (Buenos Aires, Argentina) during non-breeding period. We studied differences in the diet of this species in Mar Chiquita Lagoon during three consecutive non-breeding seasons. Diet was assessed by analysis of regurgitated pellets. The varunid crabs were the most important'preys, with Neohelice granulate (70%) being dominant numerically over Cyrtograpsus angulatus (30%) throughout the non-breeding cycle. Other crab species, insects, and fish were occasionally present in the diet. The proportion of sexes consumed was biased to the males for N. granulate and to females of C. angulatus. In the first case, the bias to the consumption of males could be linked to these individuals are most often at the entrance of their burrows than females and thus be more exposed to predation. The largest average size of N. granulate was consumed during the autumn of 2005 and 2006 and in winter 2004. The average size of C. angulatus was significantly different between winter and spring seasons during 2005 and 2006.

• 出版日期2010