Date of Award
Master of Science
Diana J.R. Lafferty
The gut microbiome (GMB), the mutualistic microbial communities located in the gastrointestinal tract (GIT), has co-evolved in vertebrates to perform micro-ecosystem services to facilitate physiological functions. Despite the key role of the GMB in host health, wildlife managers have been slow to consider the ramifications of anthropogenic pressures to wildlife-GMB diversity. For example, although diet is one of the most influential determinants of a host’s GMB, many wildlife agencies allow baiting with human-provisioned foods to facilitate the harvest of wildlife such as American black bear (Ursus americanus). Additionally, much of our knowledge of wildlife-GMB relationships is based on studies of colon GMB communities derived from the feces of captive specimens. To better understand wildlife-GMB relationships, I first aimed to characterize wild black bear GMB communities in the colon and jejunum, two functionally distinct regions of the gastrointestinal tract (GIT). Second, I estimated the proportional contribution of human-provisioned foods to the diets of black bear and evaluated the effect of human-provisioned foods on the GMB at each GIT site. I engaged hunters as citizen scientists to collect biological samples from legally harvested black bears, 16S rRNA gene amplicon sequencing to identify microbial taxa, and stable isotope analysis of black bear hair to estimate diet. My results suggest that the jejunum and colon of black bears do not harbor significantly different GMB communities, but that increased proportions of human-provisioned foods in black bear diet, specifically corn, and significantly reduces GMB diversity.
Gillman, Sierra, "THE GUT MICROBIOTA OF A WILD AMERICAN BLACK BEAR (Ursus americanus) POPULATION" (2020). All NMU Master's Theses. 612.