Age-Related Variation in the Scent Pouch Bacterial Communities of Striped Hyenas (Hyaena hyaena)

Abstract

Our understanding of the contributions of symbiotic microbes to animal behavior is being greatly facilitated by technological advances in characterizing host-associated microbial communities and their synergistic metabolic activities. A particularly promising line of inquiry is to elucidate how symbiotic microbes can mediate animals’ chemical communication systems. Using a combination of next-generation DNA sequencing and targeted metabolite analyses, we recently found that symbiotic bacterial communities appear to contribute to scent pouch odors among wild striped hyenas. Here we characterize these bacterial communities among juvenile, young adult, and adult hyenas. Akin to adult scent pouches, juvenile pouches are populated by fermentative bacteria from known odor-producing clades. However, the composition and structure of bacterial communities in juvenile scent pouches are different from, and more variable than, those of communities inhabiting the pouches of adults. Adult striped hyenas possess a core scent pouch bacterial community—12 bacterial types were shared among all sampled adults and consistently accounted for more than 90 % of the recovered 16S rRNA gene sequences. These bacterial types were less widespread and abundant among juveniles. Although verification will ultimately require longitudinal sampling of individual hyenas throughout ontogeny, these data are consistent with the hypothesis that striped hyena scent pouch bacterial communities converge on a stereotypical phenotype during host development. We discuss how this could be facilitated by transmission of bacterial community members from adult scent pouches to those of juveniles by juveniles and adults occupying the same spaces, coming into recurrent physical contact, and/or scent overmarking each other.