Detection of Extra-Pair Paternity in Captive Gentoo Penguins Using Genetic Analysis

Molecular genetic studies have revealed extra-pair paternity (EPP) in monogamous avian species including several penguin species. Therefore, this study investigated the parentage of captive gentoo penguins (Pygoscelis papua) in Japanese zoos and aquariums by analyzing 10 microsatellite loci. A total of 200 relationships between parents and offspring from the studbook were created through behavioral observations. Three of these cases (1.5%) showed mismatched genotypes between the father and offspring in at least three loci, thereby suggesting the possibility of EPP. In two of the three cases, the true (genetic) fathers were inferred from male individuals who lived with their mothers during the breeding season. The EPP frequency in the captive population was lower than that previously reported for wild populations. The results of this study demonstrate that the genetic approach effectively validated the accuracy for studbook of captive avian species.