Grooming partners of immature blue monkeys (Cercopithecus mitis) in the Kakamega Forest, Kenya

I report results of a 4-year study, which profiles grooming partners of imm ature blue monkeys in a Kenyan rain forest. The analysis focuses on the deg ree to which mothers and offspring were preferred grooming partners and on sex differences in grooming partners. Subjects ranged in age from 0 to 6 ye ars and were members of one study group in which kinship relations were kno wn from long-term study. Immatures often had their mothers as the top-ranke d partner. Even more reliably, however, adult females had their offspring a s top-ranked immature partners. As offspring grew older, they tended to fal l in the rank ordering of their mothers' immature grooming partners, especi ally when young siblings were born. Immature males had fewer grooming partn ers overall than female peers did. Thus, immature females diversified their partners more than males did, especially by establishing grooming relation s with immature female partners. Immatures of both sexes had more female pa rtners than expected by chance. Observed sex differences suggest that immat ure female blue monkeys may use grooming to cultivate relationships with lo ng-term future benefits. It is less clear that the grooming of immature mal es functions in this way. Immatures of both sexes may also use grooming to maintain relationships of current value, to practice for future social exch ange, and to keep clean, and some of their grooming may be in the primary i nterest of their partners, rather than themselves. In general, immature blu e monkeys resemble the immatures of other catarrhine taxa in the way in whi ch grooming is distributed among various partners.