Mapping the social network: tracking lice in a wild primate (Microcebus rufus) population to infer social contacts and vector potential

We show that louse transfers involved 43.75% of the studied lemur population, exclusively males. Louse transfers peaked during the breeding season, perhaps due to increased social interactions between lemurs. Although trap-based individual lemur ranging patterns are restricted, louse transfer rate does not correlate with the distance between lemur trapping locales, indicating wider host ranging behavior and a greater risk of rapid population-wide pathogen transmission than predicted by standard trapping data alone. Furthermore, relatively few lemur individuals contributed disproportionately to the rapid spread of lice throughout the population.Using a simple method, we were able to visualize exchanges of lice in a population of cryptic wild primates. This method not only provided insight into the previously unseen parasite movement between lemurs, but also allowed us to infer social interactions between them. As lice are known pathogen vectors, our method also allowed us to identify the lemurs most likely to facilitate louse-mediated epidemics. Our approach demonstrates the potential to uncover otherwise inaccessible parasite-host, and host social interaction data in any trappable species parasitized by sucking lice.Ectoparasites have evolved with their hosts for millenia, resulting in highly intimate host-parasite relationships [1,2]. Due to the intimacy of such relationships, studies of host-parasite interactions have the potential to provide novel insights into the ecology of both organisms involved and data collected on one of the partners can have implications for the other. Previous studies have directly monitored host resource usage and contacts to provide improved predictions about parasite and pathogen transmission [3]. However, direct observation of social interactions is not feasible in species that are nocturnal, arboreal, subterranean or otherwise elusive. Additionally, direct transfers of ectoparasites between individually identifiable hosts has been d