Annual and Seasonal Variability in Tundra Vole (Microtus oeconomus) Diet

• Main Author: Lisi, Mary Kathleen
• Format: Text
• Language: unknown
• Published: University of New Hampshire Scholars' Repository 2024
• Subjects: arctic; diet; herbivory; stable isotope analysis; tundra vole; Carex bigelowii; Climate change; Eriophorum; Tundra; Alaska
• Online Access: https://scholars.unh.edu/thesis/1833; https://scholars.unh.edu/context/thesis/article/2874/viewcontent/Lisi_unh_0141N_11737.pdf

Within arctic ecosystems, small mammals (voles and lemmings) influence plantcommunity composition, soil nutrient availability, and carbon cycling through foraging and the deposition of waste. Yet, little is known about rodent diet specifically and how it may vary annually and seasonally. Here, we characterize the composition and stability in tundra vole (Microtus oeconomus) diet in northern Alaska using stable isotope analysis of fecal and hair samples collected over a seven-year period. Results from Bayesian stable isotope mixing models from both fecal and hair sample data show that tundra voles in northern Alaska predominately feed on rhizomatous sedges, Eriophorum vaginatum and Carex bigelowii, throughout the summer season. However, the plant part consumed shifts from rhizomes in early summer to tillers and buds in late summer after green-up. We found strong overlap in diet composition among years and an increase in tundra vole dietary niche breadth with population abundance. By studying diet, we can gain a better understanding of plant-animal interactions in the Alaskan tundra and how these interactions may shift under climate change or other disturbances.