Evaluation of male inter-troop transfer as a mating strategy among ring-tailed lemurs on St. Catherines Island, USA.

One commonly cited function of dispersal is to increase mating opportunities. In this study, I evaluated the hypothesis that male inter-troop transfer is used as a mating strategy in ring-tailed lemurs, Lemur catta, on St. Catherines Island (SCI), Ga., USA. I measured male mating success and inter-troop transfer behavior across 5 years in a population consisting of 4 lemur groups on SCI. Data strongly supported dispersal as a successful mating strategy of natal males, because these males did not mate within their natal groups, but always mated in their new groups of entry. For secondary male dispersal (transfers between 2 non-natal groups), data on 2 males collected in breeding seasons immediately prior to and following transfer show that their individual mating success measures increased following a transfer. Data revealed that among non-natal males, high-ranking males on SCI were more likely to transfer between groups than lower-ranking males, which is somewhat contrary to the more common trend among primates of lower-ranking males transferring more frequently. In sum, male primary dispersal appears to function as a mating strategy among male L. catta on SCI, with indications that secondary dispersal may also be successful at increasing male mating success.