Exploring DNA Metabarcoding to Understand Diet in Declining Columbian Sharp-Tailed Grouse (\u3cem\u3eTympanuchus phasianellus\u3c/em\u3e)

Abstract

The Columbian Sharp-tailed Grouse (Tympanuchus phasianellus; hereafter CSTG) formerly occupied shrub-steppe ecosystems across western North America but now inhabit less than five percent of their former range due to habitat loss and other anthropogenic factors. Despite their social and ecological significance, research on CTSG diet has been limited, with the last comprehensive study taking place over 20 years ago. Understanding dietary habits is crucial, as food availability directly impacts population dynamics, local adaptation, and overall fitness of this species. Through the application of plant DNA metabarcoding (i.e., p6 loop of trnL) from non-invasively collected fecal samples, this study identifies plants consumed by CSTG across western North America. Preliminary results from 2022-2023 indicate that the spring diet of CSTG includes a large abundance of taxonomic reads from the plant families Apiaceae (parsley family) and Asteraceae (composite family). While there is not a significant difference between years, there is a significantly higher diversity of plants eaten in British Columbia than populations in Idaho, Washington, or Wyoming. Additional 2024 samples will be sequenced this summer, with 2025 samples in preparation. This preliminary work sets the foundation for future studies to shape habitat management and restoration strategies for CSTG, supporting long-term conservation efforts