Midwest Fish & Wildlife Conference 2019

AUTHORS: William Peterman, Andrew Hoffman, Annalee Tutterow – Ohio State University

ABSTRACT: Temperature is of paramount consideration for ectothermic animals. Numerous studies have previously described multiscale habitat selection and use in timber rattlesnakes (Crotalus horridus). However, there is currently limited understanding of how habitat use and selection are related to the thermal landscape. The primary objectives of this study are to understand how the thermal landscape is affected by land use and forest management, and how spatial and temporal habitat use by timber rattlesnakes relates to the thermal landscape. To create a down-scaled near-surface air temperature model, we deployed remote temperature loggers across our focal landscape in Southeast Ohio. We then used fine-scale LiDAR data to derive spatial topographic surfaces as well as surfaces describing forest structure. Using these models, we related the predicted spatial-temporal air temperatures to field observations of radio telemetered snake locations, as well to snake body temperature data collected using internal temperature data loggers.Our near-surface air temperature and snake body temperature models both fit the data well with high predictive power. Unsurprisingly, we found that gravid females, on average, occupied areas of the landscape with higher temperatures than non-gravid snakes. We have observed large differences in parturition dates in our population. Females that give birth earlier in the summer are occupying areas that are warmer than areas occupied by females that give birth later in the summer. Our study provides a novel perspective of habitat use in timber rattlesnakes, and adds to the limited knowledge of timber rattlesnake ecology in the Midwest. A clear understanding of the landscape features affecting near-surface air temperatures and the spatial thermal ecology of timber rattlesnake has the potential to facilitate more effective and targeted habitat management.