Forming strong social bonds can lead to higher reproductive success, increased longevity, and/or increased infant survival in several mammal species. Given these adaptive benefits, understanding what determines partner preferences in social bonding is important. Maternal relatedness strongly predicts partner preference across many mammalian taxa. The role of paternal relatedness, however, has received relatively little attention, even though paternal and maternal kin share the same number of genes, and theoretically similar preferences would therefore be expected for paternal kin. Here, we investigate the role of maternal and paternal relatedness in female affiliation in Assamese macaques (Macaca assamensis), a species characterized by a relatively low male reproductive skew. We studied a wild population under natural conditions using extensive behavioral data and relatedness analyses based on pedigree reconstruction. We found stronger affiliative relationships and more time spent grooming between maternal kin and paternal half-sisters compared with nonkin, with no preference of maternal over paternal kin. Paternally related and nonrelated dyads did not form stronger relationships when they had less close maternal kin available, but we would need a bigger sample size to confirm this. As expected given the low reproductive skew, affiliative relationships between paternal half-sisters closer in age were not stronger than between paternal half-sisters with larger age differences, suggesting that the kin bias toward paternal kin was not mediated by age similarity. An alternative way through which paternal kin could get familiarized is mother- and/or father-mediated familiarity.

中文翻译：

---

女阿萨姆猕猴偏向父系和母系

在几种哺乳动物中，形成牢固的社会纽带可以导致更高的生殖成功率，更长的寿命和/或更高的婴儿存活率。鉴于这些自适应的好处，了解决定社会交往中的伴侣偏好的因素很重要。产妇的相关性强烈预测了许多哺乳动物分类中的伴侣偏好。然而，尽管父系和母系拥有相同数量的基因，但父系亲缘关系的作用却很少受到关注，因此从理论上讲，对于父系的亲属也有相似的偏好。在这里，我们调查了阿萨姆猕猴（Macaca assamensis）中女性隶属关系在母性关系中的作用。我们使用广泛的行为数据和基于谱系重建的相关性分析研究了自然条件下的野生种群。我们发现，与非亲属相比，母系亲属和父系同父异母姐妹之间的亲属关系更牢固，花时间更多，而母系优先于父系亲属。当亲本和非亲本二联体的亲戚亲属关系较差时，它们之间的关系并不牢固，但我们需要更大的样本量来证实这一点。正如预期的那样，由于较低的生殖偏斜，年龄较近的父亲半姐妹之间的亲属关系并不比年龄差异较大的父亲半姐妹之间的亲属关系更强，这表明年龄相似的父辈对亲属的亲属偏见没有得到调节。