Using visual evidence of mogollon voles (Microtus mogollonensis) to predict their presence in Northern Arizona

Mogollon voles (Microtus mogollonensis) live in grassy areas primarily in ponderosa pine (Pinus ponderosa) forests. We evaluated effectiveness of measuring visual evidence of Mogollon voles to monitor their populations. We used presence of five types of visual evidence and a combined measure (Index of Visual Evidence) to examine relationships between rate of capture of voles, presence, and visual evidence. We conducted our study in six meadows in ponderosa pine forests in northern Arizona, comparing evidence of presence of voles and rate of capture in an area with high density to an area with low density of voles in each meadow. We used linear regression to determine associations between visual evidence of voles and rate of capture, and we used logistic regression to investigate which visual evidence of voles were best predictors of presence. Relative abundance of voles was correlated with all types of visual evidence of voles. Relative density of fresh feces was the best predictor of rate of capture, but the Index of Visual Evidence was the best predictor of presence of voles. To monitor Mogollon voles, resource managers could use the Index of Visual Evidence, or search for fresh fecal material on runways.