Abstract

ZUMPANO, Francisco  and  GARCIA, Germán Oscar. INTRA-SPECIFIC INTERACTIONS DURING GROUP FEEDING IN THE OLROG’S GULL (LARUSATLANTICUS). Hornero [online]. 2022, vol.37, n.1, pp.5-5. ISSN 0073-3407.

In this study, we analyzed the intra-specific interactions that occur between individuals of Olrog’s Gull (Larus atlanticus) while foraging in groups outside the breeding season. Interactions were studied by analyzing behavioral observations of foraging individuals (n=171) at the Mar Chiquita Coastal Lagoon (Buenos Aires Pro-vince, Argentina). We recorded a total of 98 trophic displacements events and 70 kleptoparasitic events, in which successful attacks were 95% and 24% respectively. Juveniles and males initiated de interactions in the 77% of the trophic displacements and 65% of the kleptoparasitic events. The attacks were "with physical con-tact” in the 55% and 32% of the trophic displacements and kleptoparasitic events, respectively. The main tactic response for both intra-specific interactions was “avoiding”. The probability of occurring a kleptoparasitism event was related to the prey size. We conclude that juveniles and males were the main initiators of the interac-tions studied and that the main difference between them was the success rate. This study is the first to analyze and discuss the intra-specific interactions that occur between individuals of Olrog’s Gull. Understanding their feeding behavior is important to discover new aspects of natural history and to provide background informa-tion for a threatened endemic species.

Keywords : Argentina; foraging; kleptoparasitism; Larus atlanticus; seabirds; trophic displacements.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )