Cayo Santiago and ONPRC samples

Rhesus gut biome and behavior This project explores the relationship between primate social interaction and gut microbial ecology in rhesus macaques, Macaca mulatta. Rhesus macaques have a close phylogenetic relationship with humans, as well as a high degree of physiological and behavioral similarity. The majority of the samples will be collected from rhesus on on Cayo Santiago, a 38 acre island off the southeast coast of Puerto Rico, home to approximately 1400 free ranging macaques. This population was founded in 1938 from 409 Indian rhesus and has been maintained over the years by the Carribean Primate Research Center (CPRC). As rhesus macaques on Cayo Santiago exhibit social behavior typical of wild populations, this population provides a unique opportunity to efficiently gather fecal samples in order to assay gut microbiota and relate these data to natural variations in social behavior. Rhesus macaques live in closed social groups containing multiple adult males and females, which are organized according to rigid dominance hierarchies. Dominance is established by physical combat in males, and is transient. Females form stable linear dominance hierarchies, with daughters securing the rank immediately below their mothers during pre-pubescence. The female hierarchy is further structured into matrilines, which are made up of females who are closely related and close in dominance rank. Through census information and genetic markers, the pedigree provided by the CPRC can establish maternal and paternal assignment for most animals born since 1990 (~3000 animals), which will enable me to calculate relative contributions of genetic and social factors on the microbiome. Ongoing behavioral observations permit the reconstruction of social networks within the largest group on the island. The frequency and extent of various grooming partnerships are particularly of interest, as the frequent hand-to-mouth movements typical of grooming bouts should serve to facilitate the horizontal transmission of microbes. I will investigate whether the similarities between gut microbiomes mirror the strength of social network ties, whether microbiome profile varies substantially between social groups, and whether social hierarchy position influences microbiome. I will also investigate whether age, sex, and season influence microbiome composition and diversity in rhesus macaques.