Molecular evidence of extra-pair paternity and intraspecific brood parasitism in Magellanic Penguin (Spheniscus magellanicus)

ANNA CAROLINA MILO MARASCO; JOÃO STENGHEL MORGANTE; MELINA BARRIONUEVO; ESTEBAN FRERE

Congreso; 9th International Penguin Congress; 2016

Recent studies have shown that, despite most of the avian species being socially monogamous, they present different reproductive strategies, such as extra-pair paternity (EPP) and intraspecific brood parasitism (IBP). We investigated the genetic mating system of Magellanic penguins (Spheniscus magellanicus), a seabird species that is supposed to be extremely monogamous, with low or no evidence of extra-pair paternity, due to philopatry, partners faithfulness among years and intense biparental care. During two breeding seasons (2010 and 2011) we sampled 170 individuals of 44 different nests from Isla Quiroga colony (88 offspring, 38 putative mothers and 44 putative fathers) and the parentage was determined based on the analysis of 9 microsatellites markers. Extra-pair paternity was detected in 31% of all offspring and 48% of the nests had at least one extra-pair young. In addition, 6% of chicks were not the offspring of the putative mother or either member of the social pair, indicating evidence of intraspecific brood parasitism. These results reveals a low rate of IBP, but a high rate of EPP, both previously undescribed for this species and shows that Magellanic Penguins successfully engage in extra-pair copulations.