High level of extrapair fertilizations in individual Tibetan azure-winged magpies and their adaptive responses

Extrapair fertilizations (EPFs) occur widely in socially monogamous birds and result in mixed parentage in the brood. The response of an individual to these EPFs of its social mate remains poorly investigated in terms of parental care for the mixed brood. We addressed this question in a cooperatively-breeding corvid, the azure-winged magpie Cyanopica cyana. Parentage analysis indicated that 45% of females and 37% of males engaged in EPFs. There were 49% of cooperative groups and 36% of bi-parental nests with extrapair paternity (EPP) offspring, and 22% of cooperative groups and 19% of bi-parental nests with extrapair maternity (EPM) offspring. Based on the identity of offspring, we classified adults into four types: EPP offspring fathers/mothers, EPM offspring fathers/mothers, cuckolded males/females, and faithful males/females. A comparison of provisioning rates among all four types of breeders showed that 1) EPM offspring fathers had the highest provisioning rate; 2) cuckolded males d...

额外配对受精（Extrapair Fertilizations, EPFs）广泛存在于社会单配制鸟类中，会导致窝雏出现混合亲权现象。目前从混合亲权窝雏的亲代抚育角度，对个体响应其社会配偶此类额外配对受精行为的相关研究仍较为匮乏。我们以合作繁殖的鸦科鸟类——灰喜鹊（azure-winged magpie, Cyanopica cyana）为研究对象，探讨了这一科学问题。亲权鉴定结果显示，45%的雌性个体与37%的雄性个体存在额外配对受精行为。存在额外配对父权（Extra-pair Paternity, EPP）后代的合作繁殖群与双亲巢占比分别为49%与36%；存在额外配对母权（Extra-pair Maternity, EPM）后代的合作繁殖群与双亲巢占比则分别为22%与19%。根据后代的亲权归属，我们将成年个体划分为四类：额外配对父权后代的父/母本、额外配对母权后代的父/母本、遭配偶婚外配的雄/雌亲，以及忠实的雄/雌亲。对四类繁殖个体的育雏投喂率进行比较后发现：1）额外配对母权后代的雄性亲本具有最高的育雏投喂率；2）遭配偶婚外配的雄性个体……