MICROHABITAT AFFINITIES OF SMALL MAMMALS IN SOUTHWESTERN OKLAHOMA

Abstract

We assessed the influence of 19 microhabitat factors on the distribution and abundance of small mammals at 60 plots across Fort Sill Military Reservation in Comanche County, Oklahoma. Trapping took place each spring from 1989 to 1992. We collected 15 small mammal species and used 10 of these (Chaetodipus hispidus, Cryptotis parva, Microtus ochrogaster, Neotoma floridana, Peromyscus attwateri, P. leucopus, P. maniculatus, Reithrodontomys fulvescens, R. montanus, and Sigmodon hispidus) in our analyses. Microhabitat variables for each mammal species were evaluated as unweighted measures based on the presence or absence of each species at a plot and as weighted measures based on the abundance of each species at each plot. Both weighted and unweighted data were subjected to cluster analysis, principal components analysis, and discriminant-function analysis. General trends of the microhabitat affinities of species in each cluster were summarized on principal components. Four species (C. hispidus, N. floridana, P. attwateri, and P. leucopus) occupied barren or rocky areas with a tall herbaceous or woody canopy, and 6 species (C. parva, M. ochrogaster, P. maniculatus, R. fulvescens, R. montanus, and S. hispidus) preferred open grassy areas. Weighted discriminant analysis produced better predictive accuracy (75% correctly classified) than the unweighted data (63% correctly classified). Total number of broadleaf trees and rocky ground cover were the most important factors in discriminating among groups.