Infant handling (holding or carrying) by adult males is rare in mammals; however, high levels have been reported in some primates. Though infant handling is a costly behaviour, there are many benefits that male handlers can accrue. Infant handling by males is most conspicuous in platyrrhines and tends to be uncommon in catarrhines. In the latter species, research on male–infant interactions has focused on low-cost behaviours, such as proximity and grooming. However, to better understand the evolution of infant handling by males, more data on its occurrence across the Primate order are essential, even in species where it is relatively uncommon. We compare the occurrence of infant handling by males in three closely related species of catarrhine: Colobus vellerosus, C. guereza, and C. angolensis ruwenzorii. We collected focal animal samples on infants to quantify infant handling rates and durations, and found that adult male C. a. ruwenzorii handled infants much more frequently and for much longer than males in the other two species. We discuss how C. a. ruwenzorii’s unique social organization may explain high levels of infant handling by adult males in this species. More long-term and detailed comparisons of infant handling across species and populations will shed light on how sociality has shaped the evolution of this behaviour in the Primate order.

成年雄性对婴儿的处理（抱或携带）在哺乳动物中很少见；然而，据报道在一些灵长类动物中水平较高。尽管处理婴儿是一种代价高昂的行为，但男性处理者可以带来许多好处。男性对婴儿的抚摸在桔梗中最为明显，而在卡他林中并不常见。在后一个物种中，对男婴互动的研究集中在低成本行为上，例如接近和梳理。然而，为了更好地了解雄性处理婴儿的进化，更多关于它在灵长类目中发生的数据是必不可少的，即使在它相对不常见的物种中也是如此。我们由男性在狭鼻的三个密切相关的品种比较的婴幼儿处理发生：疣vellerosus，C. guereza和C. angolensis ruwenzorii。我们收集了婴儿的焦点动物样本以量化婴儿处理率和持续时间，并发现成年男性C. a. 与其他两个物种的雄性相比，ruwenzorii处理婴儿的频率更高，时间也更长。我们讨论C. a. ruwenzorii独特的社会组织可以解释该物种成年雄性对婴儿的高度处理。对不同物种和种群的婴儿处理进行更长期和详细的比较，将阐明社会性如何影响灵长类动物的这种行为的演变。