Small Mammal Habitat Preferences in a Patchwork of Adjacent Reconstructed Grasslands Subject to Semiannual Burns

Abstract

This study used small mammal capture-recapture methods within a mosaic of side-by-side prairie reconstructions to evaluate the relationship between floristic diversity, the effect of prescribed burns, and habitat use. This unique 10.4 ha study of opportunity consisted of multiple plots of three habitat types: low floristic diversity exotic cool-season grasses (CSG), low floristic diversity grass plantings dominated by native warm-season grasses (WSG), and floristically diverse, mixed prairie (MP) plantings with 45 species of forbs. Data for calculating small mammal abundances (new captures/trap effort) were determined by trapping in August following spring burns in 2002 and 2004, and unburned years in 2003 and 2005. Fire-positive species (meadow jumping mice, Peromyscus spp.) preferred fields with a more open understory (MP plantings), and a reduced thatch thickness and leaf litter layer (burned fields). Fire-negative species (meadow voles, northern short-tailed shrews) populated all restorations (CSG, WSG, MP plantings) but only during the unburned years when the fields provided a high density of vegetative cover. Even though the distinct floristic diversity found within the three reconstruction types influenced small mammal foraging preferences, the effect of semiannual burns on floristic structures had a noteworthy impact on their distributions. The results of this study demonstrate an important take home message for restoration practitioners: techniques that promote differences in structural characteristics are just as important as creating plantings with high floristic diversity.