DISTRIBUTION OF BLACK-TAILED JACKRABBIT HABITAT DETERMINED BY GIS IN SOUTHWESTERN IDAHO

We developed a multivariate description of black-tailed /d jackrabbit (Lepus californicus) habitat associations from Geographical Informatio n Systems (GIS) signatures surrounding known jackrabbit locations in t he Snake River Birds of Prey National Conservation Area (NCA), in sout hwestern Idaho. Habitat associations were determined for characteristi cs within a l-km radius (approx home range size) of jackrabbits sighte d on night spotlight surveys conducted from 1987 through 1995. Predict ive habitat variables were number of shrub, agriculture, and hydrograp hy cells, mean and standard deviation of shrub patch size, habitat ric hness, and a measure of spatial heterogeneity. In winter, jackrabbits used smaller and less variable sizes of shrub patches and areas of hig her spatial heterogeneity when compared to summer observations (P < 0. 05). During the low population phase, jackrabbits also used agricultur al regions more during winter than summer. The association with agricu ltural regions was emphasized spatially in a GIS map contrasting winte r and summer periods. Multivariate habitat means (P < 0.001), but not individual GIS variables (P > 0.05), differed significantly between hi gh and low population phase. We used the Mahalanobis distance statisti c to rank all 50-m cells in a 440,000-ha region relative to the multiv ariate mean habitat vector. On verification surveys to test predicted models, we sighted jackrabbits in areas ranked close to the mean habit at vector. Areas burned by large-scale fires between 1980 and 1992 or in an area repeatedly burned by military training activities had great er Mahalanobis distances from the mean habitat vector than unburned ar eas and were less likely to contain habitats used by jackrabbits.