Behavioral correlates of extra-pair copulation in Indri indri.

Active pursuit of extra-pair mating has been reported for Indri indri, the socially monogamous largest living lemur. This study, conducted in a mountain rainforest in eastern Madagascar, presents the first evidence for extra-pair mating of indri and discusses the alternative mating strategy and alteration of the social, territorial, spatial, and vocal behavior of the adult female of a group of wild indris. Further studies may investigate whether extra-pair copulation is an attempt to breed with a partner of superior quality and thus lead to extra-pair paternity. If so, it could potentially play a role in maintaining genetic variability within a population.