Quantifying the Effects of Habitat Disturbance on the Timber Rattlesnake, Crotalus horridus, in Northeastern Pennsylvania

This project examined the relationship between anthropogenic habitat disturbance and population levels in Crotalus horridus (Timber Rattlesnake). This study relied on population and habitat information collected by the Pennsylvania Fish and Boat Commission (PFBC) during a previous study known as the Timber Rattlesnake Assessment Project (TRAP). Geographic Information Science (GIS) was utilized to measure landscape features such as canopy coverage, trails, and road density through habitat utilized by Timber Rattlesnakes. Using the information from TRAP, in conjunction with GIS technology, quantitative results were produced and analyzed to construct a clear picture of how human habitat alterations affect Timber Rattlesnake populations. The results were primarily derived from two main models, (1) a linear regression with a normalize distribution and (2) a generalized linear model with a binomial distribution. An inverse relationship was found between rattlesnake populations and proximity and density of buildings at the large spatial scale. These findings suggest that anthropogenic disturbance impacts Timber Rattlesnakes negatively in the commonwealth. The weak relationships between the variables assessed may be, in part, attributable to the use of TRAP reports which were mostly based on one or two site visits and not intended to provide population estimates. Further work will be necessary to refine our models, including improved population estimates and expansion of our work to the entire commonwealth.