Comparative Analysis of Diet Composition and Dietary Diversity in Wild Przewalski’s Gazelle and Sympatric Domestic Sheep Around Qinghai Lake, Western China

Understanding dietary relationships between wild ungulates and sympatric livestock is important for conserving threatened species in alpine grassland ecosystems. Przewalski’s gazelle (Procapra przewalskii) is an endangered ungulate endemic to the Qinghai Lake Basin, but its dietary relationship with sympatric domestic sheep across multiple subpopulations remains poorly understood, particularly at finer taxonomic scales. Using fecal microhistology of April 2023 samples from eight study sites during the late winter grazing season, we compared dietary composition, diversity, evenness, niche breadth, and overlap at the family, genus, and species levels. More plant taxa were identified in the fecal samples of Przewalski’s gazelle than in those of domestic sheep, and estimates of dietary diversity, evenness, and niche breadth were generally higher for gazelles. Both herbivores relied largely on graminoids, indicating a shared dietary foundation. However, dietary overlap was higher at the family level (Pianka’s index = 0.830–0.976) than at the genus (0.718–0.946) and species (0.629–0.946) levels, with substantial variation among subpopulations. These results suggest a shared broad dietary foundation but apparent differentiation in resource use at finer taxonomic scales during late winter. These findings can inform Przewalski’s gazelle conservation and grassland management in the Qinghai Lake Basin.