Are you my baby? Testing whether paternity affects behavior of cobreeder male acorn woodpeckers

Natural selection is expected to favor males that invest more in offspring they sire. We investigated the relationship between paternity and male behavior in the acorn woodpecker (Melanerpes formicivorus), cooperative breeders that live in family groups including offspring that remain on their natal territory, sometimes for years, and cobreeders of both sexes. Regardless of group composition, only one communal nest is attended at a time. Whereas cobreeding females share maternity equally, one male often sires the majority of young in the group’s communal nest. Copulations are rarely observed, and thus it has not been possible to link paternity to sexual behavior. There were no differences among cobreeder males that did or did not sire young in their propensity to roost in the nest cavity at night. However, cobreeder males that attended females continuously prior to egg-laying were more likely to successfully sire young than males that did not, and the relative share of feeding visits an...

自然选择被认为会青睐对自身所繁殖后代投入更多资源的雄性。我们研究了橡树啄木鸟（acorn woodpecker, Melanerpes formicivorus）中父权与雄性行为的关系——这类合作繁殖鸟类生活在家庭群体中，成员包括留在出生地领域（有时可达数年）的后代及雌雄两性的共同繁殖者。无论群体组成如何，同一时间仅照料一个公共巢穴。尽管共同繁殖的雌性会平等分享母权，但群体公共巢穴中的大多数幼鸟往往由单只雄性所繁殖。交配行为极少被观察到，因此无法将父权与性行为直接关联。在夜间栖息于巢穴洞穴的倾向方面，成功繁殖幼鸟与未成功繁殖的共同繁殖雄性之间并无差异。然而，产卵前持续陪伴雌性的共同繁殖雄性，其成功繁殖幼鸟的概率高于未持续陪伴的雄性，且喂食访问的相对比例...