The Wildlife Society Conference 2022

Mountain Goat Diets from Pellet Metabarcoding

S. Scoresby, Student Contractor, U.S. Geological Survey, Northern Rocky Mountain Science Center, 38 Mather Drive, PO Box 169West Glacier, MT 59936, salix.scoresby@gmail.com. Co-Authors: Dr. Tabitha Graves, Teagan Hayes

The diet of mountain goats (Oreamnos americanus) is notoriously hard to study as they are habitat specialists in rugged and remote alpine environments. Although they are dietary generalists with highly variable diets across systems, recent work found mountain goat populations in Glacier National Park declined by ~45% since 2008 and that this population change was associated with changing climate. Both temperature and precipitation influence forage phenology, diversity, productivity and ultimately plant communities. In 2019 we instituted a project collecting mountain goat pellets.  From May to September, trained citizen science volunteers and technicians collected pellets at 46 locations across Glacier National Park. Using samples genetically identified as mountain goat, we metabarcoded 52 samples, assaying for vegetative content to the most specific level possible. Identification specificity relies on partially or completely matching genotypes to previously genotyped plant species. We found exact sequence variants for >72 species from >65 families of plants, with 7 families composing 33% of the items identified in the summer diet. This method of ascertaining diet provides improved data over older diet analysis methods such as vegetation transects, manual pellet examination, and stomach content analysis. Understanding the diet composition for these specialized mountain ungulates can inform effective management techniques, especially in light of rapid climate change in alpine environments.