Seasonal Gut Microbiome Variation Associated With Both Climate and Wildlife Tourism in Asian Elephants (Elephas maximus).

The health, survival, and fitness of wild animals depend on their responses to seasonal variation in natural and anthropogenic environmental factors. The gut microbiome is a unique, non-invasive tool for assessing the magnitude of these responses, but few studies collect longitudinal gut microbiome data from wild populations. Here, we begin to address this gap in a population of Asian elephants in Sri Lanka that experience variation in both natural and anthropogenic factors across seasons. Using 16S rRNA gene amplicon data from elephants in two national parks collected over 6 months, we test the hypothesis that Asian elephant gut microbiome composition varies across months in association with both climate and tourist activity. We find that both national park and sampling month are associated with significant differences in elephant gut microbiome composition, and a portion of the observed temporal variation is associated with tourist vehicle traffic. These results provide an important foundation from which to build knowledge regarding how natural and anthropogenic factors interact with and affect elephant health.