Body site-specific microbiota reflect sex and age-class among wild spotted hyenas

Abstract

Host-associated microbial communities, henceforth ‘microbiota’, can affect the physiology and behavior of their hosts. In mammals, host ecological, social and environmental variables are associated with variation in microbial communities. Within individuals in a given mammalian species, the microbiota also partitions by body site. Here, we build on this work and sequence the bacterial 16S rRNA gene to profile the microbiota at six distinct body sites (ear, nasal and oral cavities, prepuce, rectum and anal scent gland) in a population of wild spotted hyenas (Crocuta crocuta), which are highly social, large African carnivores. We inquired whether microbiota at these body sites vary with host sex or social rank among juvenile hyenas, and whether they differ between juvenile females and adult females. We found that the scent gland microbiota differed between juvenile males and juvenile females, whereas the prepuce and rectal microbiota differed between adult females and juvenile females. Social rank, however, was not a significant predictor of microbiota profiles. Additionally, the microbiota varied considerably among the six sampled body sites and exhibited strong specificity among individual hyenas. Thus, our findings suggest that site-specific niche selection is a primary driver of microbiota structure in mammals, but endogenous host factors may also be influential.

Measuring Salivary Cortisol in Wild Carnivores

“…There are at least two possible explanations for the discrepancies. First, sex differences in gut composition might lead to sex differences in fecal glucocorticoid metabolites without affecting salivary cortisol (Goymann, 2012;Rojas et al, 2020). Second, juveniles sampled via saliva tended to be younger than juveniles sampled via feces in earlier studies (Greenberg, 2017), perhaps affecting the trends we found.…”

Antibiotic Resistance of Bacteria in Two Marine Mammal Species, Harbor Seals and Harbor Porpoises, Living in an Urban Marine Ecosystem, the Salish Sea, Washington State, USA

“…Collecting appropriate proportions of varying age classes for valid comparisons in wildlife studies presents challenges when relying on passive collection of stranded animals. Although not well studied, differences in age class-related resistance between harbor seals and porpoises may reflect differences in microbiome composition such as the nascent fecal biome of pups and calves compared to older animals as has been described in spotted hyenas (Crocutta crocutta) [59].…”

The microbiome impacts host hybridization and speciation

“…Microbiomes, inclusive of intracellular and extracellular microorganisms, are often distinguishable across host body sites within species [ 14 – 20 ]. Within each site, they can act in a context-dependent manner as harmful, helpful, or harmless to hosts—with potentially integrated metabolisms and interacting gene products ( Fig 1 ) .…”