Spatiotemporal distribution of individuals as an indicator for the social system of Lepilemur sahamalaza

Primate social systems are highly diverse, complicating the classification of particularly elusive species that are difficult to observe. The spatial distribution of individuals over time is a critica lindicator for the social organization and long-term studies are important to establish patterns of social interactions. In recent years, species of the cryptic, nocturnal sportive lemurs of the genus Lepilemur were found to live in pairs in which a single male and a single female share and defend a mutual home range. The present study aimed to forward research into this underrepresented genus by determining the social organization and structure of the Sahamalaza sportive lemur, L. sahamalaza. We collected 773.15 hr of behavioral and GPS data during a period of 10 months (between 2015 and 2016) on 14 individuals: eight females and six males. There was no evidence of pair-specific home range use as intra- and intersexual home range overlap was high. No pattern of social interactions between focal individuals could be distinguished despite high range overlap. Individuals met and interacted infrequently, resulting in an interaction rate of 0.32 interactions/hr. Sleeping associations between adult individuals were never observed. While both sexes had access to multiple potential mating partners, range sizes or ranging distances did not increase in mating periods. Overall, the social system of Sahamalaza sportive lemurs exhibits aspects of a solitary social organization and structure with potential for the polygamous mating system. These findings underline the importance of detailed social ecology studies that can provide the basis for understanding potential environmental influences on social system variability of closely related species.