Spatial Ecology of the Timber Rattlesnake (Crotalus Horridus) From the Mid-Atlantic Coastal Plain

Dreslik, Michael J.

Illinois Natural History Survey

University of Illinois Urbana-Champaign

Champaign, IL 61820 USA

Petersen, Christopher E.

Naval Facilities Engineering Command Atlantic

Norfolk, VA 23508 USA

Goetz, Scott M.

Department of Biological Sciences

Auburn University

Auburn, AL 36849 USA

Kleopfer, John (J.D.)

Virginia Department of Game and Inland Fisheries

Charles City, VA 23030 USA

Savitzky, Alan H.

Department of Biology

Utah State University

Logan, UT 84322 USA

Studies of the spatial ecology of organisms provide insights into movement rates, area used, and habitat use. Spatial studies answer such conservation-related questions as how much and when an organism moves, how much area it requires, and what factors affect both movements and activity areas. Our study aimed to determine what factors affect movement patterns and activity area sizes of Timber Rattlesnakes (Crotalus horridus) in the mid-Atlantic using data collected over a 17 year-period, which afforded us the ability to examine the effects of individual and inter-annual variation. There have been few long-term studies of the spatial ecology of this species on the Coastal Plain. We used mixed-effects general linear regression, coupled with AIC methods, to determine which predictive models best explained the variation observed in movement and activity areas. For movement, we found that the daily and annual total distances moved by male snakes were approximately two times those of females and males moved greater distances from hibernacula than females. In most cases, half of the variation was explained by differences among individuals. Similarly, activity area sizes for males were more than twice those of females, with the individual variation being a less important component. Our study suggests one aspect of snake size (mass) may play a role in the spatial ecology of this species. Importantly, we observed a positive relationship between increasing mass and size of activity areas in males, however, this trend was not seen in females.