Short-term responses of Timber Rattlesnakes (Crotalus horridus) to even-aged timber harvests in Indiana

The Timber Rattlesnake (Crotalus horridus) is a species of conservation concern throughout much of the Midwestern United States. While the habitat preferences of Timber Rattlesnakes have been studied throughout much of its range, little empirical data is available on the effects of forest management on this species. During 2007-11, we monitored movements of 47 adult Timber Rattlesnakes using radio telemetry in southcentral Indiana. Snakes were tracked during one or more seasons (April-October) for two years prior to, and three years following scheduled timber harvests (4-ha clearcuts and 4-ha understory removal as the first stage of shelterwood harvests). Annual home range estimates (100% Minimum Convex Polygon [MCP]) for both sexes combined ranged from 1.6 ha to 271.3 ha. The average home range for males (68.8 ha) was larger than for either non-gravid females (22.7 ha) or gravid females (11.7 ha). Mean home range size using MCPs or kernel density estimates did not change from pre- to post-harvest in control sites or even-aged sites for either sex. The daily distance traveled by snakes and their proportional use of areas within harvest boundaries did not differ between treatment periods. Canopy and understory removal on a small scale (approx. 4 ha) in a forested landscape did not affect seasonal or fine-scale movements of adult Timber Rattlesnakes 1-3 years post-harvest. Our results suggest that this scale of timber harvesting is compatible with Timber Rattlesnakes.