Mating Tactics in Male Grey-Cheeked Mangabeys (Lophocebus albigena)

Reproductive success of males is thought to depend mainly on access to receptive females, and therefore, males compete for females (Darwin 1859; Andersson 1994). In social species, evidence for this competition is found in the distribution of males among groups containing females (Eberle & Kappeler 2002), in male–male interactions and in their manipulation of females to increase mating opportunities (Smuts & Smuts 1993). As males vary in age, size, fluctuating asymmetry and energy reserves they can adopt different tactics or change their tactics as they grow or age to optimize their reproductive success (Waltz & Wolf 1984; Stockley et al. 1996; Cook et al. 1997; Thirgood et al. 1999; Sinervo et al. 2000; Kemp 2002; Shuster & Wade 2003; Isvaran 2005; Lidgarda et al. 2005; Saunders et al. 2005; Caillaud 2008; Lucas & Howard 2008). When male tactics are costly to females, these females can respond with counter strategies, which may lead to an arms race in sexual strategies (Agrell et al. 1998; Soltis et al. 2001). In multi-male groups of primate species, dominance among males is the most important factor determining a male’s access to females (e.g. Altmann 1962; Suarez & Ackerman 1971; Janson 1984; Dunbar 1988; Dixon et al. 1993; Altmann et al. 1996; Nishida 1997; Gust et al. 1998). However, there are few exceptions (Tutin 1979; Berard et al. 1993; Bercovitch 1997; Nishida 1997; Strier 2002). In most primate species that live in mixed-sex groups, males have a tendency to leave their natal group and move between groups as transient males (Pusey & Packer 1987; Isbell 2004). This behaviour has also been documented in our study species, grey-cheeked mangabeys (Olupot 1999; Olupot & Waser 2001). Olupot & Waser (2001) divided these males into two categories: dispersing males (here called transient), which mated in new groups after migration, and visiting males which were not Correspondence Małgorzata Arlet, Department of Entomology, University of California Davis, One Shields Avenue, Davis CA 95616, USA E-mail: [email protected]