Bauder, J.M., H. Akenson, and C.R. Peterson. 2017. Factors influencing the movement patterns of prairie rattlesnakes (Crotalus v. viridis) across a mountainous landscape in a designated wilderness area. Pages 154-167 in M.J. Dreslik, W.K. Hayes, S.J. Beaupre, and S.P. Mackessy, editors. Biology of the Rattlesnakes Vol. II. ECO Herpetological Publishing and Distribution, Rodeo, New Mexico, USA.
Abstract
Although Prairie Rattlesnakes (Crotalus v. viridis) are known to make lengthy migrations from communal hibernacula to summer foraging habitat, it is largely unknown how these patterns are influenced by mountainous topography. The objectives of this study were to determine how Prairie Rattlesnake movement patterns in a mountainous landscape were influenced by topography, habitat, and prey activity. We used radio telemetry to monitor the movements of 16 male and four nonpregnant female Prairie Rattlesnakes in the Frank Church Wilderness in central Idaho during the summer of 2008. We used GIS to test for selection for topographic features and habitats at multiple spatial scales and compared small mammal activity among habitats. Rattlesnakes moved across a wide range of topographic features including ridges, steep slopes, rivers, and creeks. Rattlesnakes appeared somewhat restricted by topography, particularly elevation, within three kilometers of their hibernacula while topography appeared to have little restrictive effect within their home ranges. Although rattlesnakes showed the greatest selection for riparian habitats at all spatial scales, we failed to detect a significant difference in small mammal activity among habitats. Our results indicate that topography does influence rattlesnake movement and that these effects vary by spatial scale. Although habitat and prey abundance likely influence rattlesnake movements in this system, topography may impose the greatest constraints on rattlesnake movements.