Date of Award

Spring 5-6-2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

First Advisor

Dominic L. DeSantis

Abstract

Roadways are among the most widespread and disruptive anthropogenic land use features that influence the behavior and movement of wildlife. Negative impacts such as vehicle-induced mortality, habitat destruction and fragmentation, and the creation of barriers to movement have been well documented across taxa, but the fine-scale behavioral impact of roadways on smaller, cryptic species has yet to be directly examined. Using a novel integration of radio telemetry and tri-axial accelerometry, we evaluated the movement response of Timber Rattlesnakes (Crotalus horridus) to roadways in central Georgia. We quantified individual C. horridus movement and space use with both radio telemetry and accelerometry derived metrics (RT and ACT metrics) across the active season (March–November) in order to investigate the influence of the mean distance to roadways on movement patterns at a broad, annual time scale. To evaluate the behavioral response of C. horridus to roadways at a finer time scale, we quantified RT and ACT metrics during confirmed road interactions (i.e., instances when individual snakes either crossed a road or were detected within 25 meters of a road but did not cross) and compared these instances to the RT and ACT metrics calculated across the remainder of the active season. Relating the annual RT and ACT metrics to the mean Euclidean distance to roadways revealed no significant associations at a broad time scale. However, the evaluation of C. horridus movement behavior during punctuated road encounters revealed that snakes increased both RT and ACT metrics during the road interactions compared to metrics calculated across the remainder of the active season. This might indicate that the abundance of contiguous habitat adjacent to roadways at our study site is serving as an adequate buffer to any long-term shifts in movement behavior, but the potential hidden cost of increasing movement when snakes encounter roads could have negative implications for populations that encounter roads more frequently than those at our site. Although intrinsic factors such as sex and behavioral season (mating and non-mating) have been documented as drivers of variation in pit viper movement patterns, the effects of sex and season were inconsistently expressed in our annual movement models. Overall, integrating radio telemetry and accelerometry and adopting a scale-dependent approach to quantifying movement allowed for a more detailed evaluation of the response of C. horridus to roadways.

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