Despite being an introduced species, feral horses are federally protected and their populations managed by the Bureau of Land Management. Studies have found that the presence of feral horses can contribute to altered soil quality, vegetation composition and small mammal biodiversity in rangeland ecosystems. Reseeding following major wildfires is a common, though under-researched practice in rangeland management. This study investigated landscape and small mammal community responses to feral horse grazing and post-wildfire reseeding in the Owyhee Mountains of Southwest Idaho. Four trapping grids were set up within each treatment area (seeded without horses, seeded with horses, native vegetation without horses, native vegetation with horses). Within each grid, soil quality was assessed through compaction, pH and texture analysis and vegetation composition was also determined. Each grid was trapped for small mammals for three consecutive nights. Small mammal diversity was highest in the native vegetation, with horses treatment area followed by the seeded, without horses treatment area. Diversity was lowest in the native vegetation, without horses treatment area. The results of this study suggest that the presence of feral horses is not necessarily damaging to rangeland ecosystems. However, more information on the effects of post-wildfire reseedings are needed.

Effects of Feral Horse (Equus caballus) Grazing and Post-Wildfire Reseeding on Small Mammals in the Owyhee Mountains of Southwest Idaho