Meeting Abstract
The range of Timber Rattlesnakes (Crotalus horridus) extends further north than most other rattlesnakes. In these colder, northern latitudes, pregnant female C. horridus must use rare, open habitats (gestation sites) in order to elevate body temperatures necessary for successful embryonic development. Unfortunately, many of these gestation sites are becoming overgrown with vegetation and it is believed females occupying these sites will no longer be able to maintain preferred body temperatures and reproductive fitness will suffer. For the past two summers (2016 and 2017) pregnant C. horridus were radio-located at six rookery sites; four of which have become overgrown with vegetation. At each site, available operative temperatures, canopy cover, and presence of potential predators was measured. Body temperatures of females were recorded every hour throughout the entire summer; as were behaviors, date of parturition, and estimated litter size. Between the two summers, trees were removed surrounding three of the six rookery sites using a targeted disturbance called “Daylighting”. Operative temperatures increased as canopies became more open. During the first summer, gravid females occupying more enclosed rookery sites dropped litters at a slightly later date, abandoned rookery sites, aborted their litters, and mothers suffered increased mortality. I will further discuss body temperatures maintained by females at rookery sites, and the efficacy of Daylighting management. Dependent on the success of this restoration technique, these management techniques can be applied throughout the species northern range to increase female reproductive success.
