Recent studies have shown that many species of apparently monogamous birds engage in extra-pair copulation (EPC). Penguins have intense shared parental care for their young, and thus have been considered monogamous. The present study aimed to assess the reproductive system of the gentoo penguin (Pygoscelis papua) on Elephant Island, Antarctica, by evaluating extra-pair paternity (EPP) and intraspecific brood parasitism (IBP). Our data revealed high rates of EPC, with approximately 48.75% of chicks originating from EPP, corresponding to 72.5% of nests. IBP was found for ~ 17% of the gentoo penguin nests, a behavior previously recorded only for Magellanic penguins (~ 6%). The reasons for these behaviors are not clear, as increased genetic diversity or sex bias of offspring was not found. Thus, social and ecological aspects could be more important for determining the costs and benefits of EPP. Other genetic and ecological aspects must be investigated in future studies, such as genetic compatibility of the immune system or fluctuations of the EPP rate due to environmental conditions.

中文翻译：

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南极象岛巴布亚巴布亚巴布亚巴布亚企鹅的双亲和种内寄生

最近的研究表明，许多显然是一夫一妻制的鸟类进行额外的交配（EPC）。企鹅对它们的孩子有强烈的共同父母照顾，因此被认为是一夫一妻制。本研究旨在通过评估额外对亲子关系 (EPP) 和种内繁殖寄生 (IBP) 来评估南极洲象岛巴布亚巴布亚巴布亚巴布亚企鹅的生殖系统。我们的数据显示 EPC 率很高，大约 48.75% 的雏鸡来自 EPP，相当于 72.5% 的巢。在大约 17% 的 gentoo 企鹅巢中发现了 IBP，以前仅记录了麦哲伦企鹅的行为（大约 6%）。这些行为的原因尚不清楚，因为没有发现后代的遗传多样性增加或性别偏见。因此，社会和生态方面对于确定 EPP 的成本和收益可能更为重要。在未来的研究中必须研究其他遗传和生态方面，例如免疫系统的遗传相容性或 EPP 率因环境条件而波动。