Bacterial communities in meerkat anal scent secretions vary with host sex, age, and group membership

The contribution of bacterial fermentation to the production of vertebrate scent signals has long been suspected, but there is still relatively little information about the factors driving variation in microbial composition in animal scent secretions. Our study subject, the meerkat (Suricata suricatta), is a social mongoose that lives in territorial, family groups and relies heavily on scent for social communication. Unusually in mammalian research, extensive life-history data exist for multiple groups inhabiting the same ecosystem, allowing for a study of both individual variation and group differences in the host's microbial communities. Using a culture-independent sampling technique, we explored the relationship between a signaler's sex, age/dominance, genotype or group membership, and the microbiota of its anal scent secretions. We found differences in the microbiota of males and females, but only after the animals had reached sexual maturity. Although bacterial communities in meerkat scent secretions were not more similar between kin than between nonkin, they were more similar between members of the same group than between members of different groups. Collectively, these results are consistent with a potential role for reproductive hormones in determining a host's bacterial assemblages, as well as an influence of sociality (such as intragroup allo-marking behavior) and/or microhabitat in the acquisition of bacterial assemblages. This study provides a key starting point for understanding the role of microbes in the variation of scent composition in mammals.