Habitat Use, Activity Patterns, and Survival of Louisiana Pinesnakes (Pituophis ruthveni) in West-central Louisiana

Abstract

Pituophis ruthveni (Louisiana Pinesnake) is considered to be one of the rarest snake species in North America and, accordingly, was federally listed as threatened under the Endangered Species Act in 2018. Although much previous work has demonstrated the species' tight association with its primary prey, Geomys breviceps (Baird's Pocket Gopher), relatively little work has been done on habitat selection, hampering management and conservation efforts. Here we use a variety of technologies, including traditional radio-telemetry, automated radio-telemetry, and subsurface temperature loggers, to monitor Louisiana Pinesnake behavior and habitat use for one of the few remaining populations of the species. We find support for previous studies indicating that Louisiana Pinesnakes exhibit bimodal seasonal activity patterns and preferences for areas with Baird's Pocket Gophers. However, we also document extensive individual variation in behavior and habitat use with some individuals exhibiting small home ranges (8.36 ha) in relatively open habitats and others with much larger home ranges (166.83 ha) in relatively closed habitats. These results suggest that Louisiana Pinesnake habitat selection, although largely restricted to areas with pocket gophers, can be extremely variable in other habitat features. Based on subsurface temperatures, our results suggest that snakes are most often found relatively close to the surface (88% of observations within 15 cm of surface) when utilizing burrows. Although we document relatively high annual survival (56%) compared to previous studies, we also detected Ophidiomyces ophiodiicola, the fungal causative agent for snake fungal disease, in 3 of our 7 individuals included in the study, highlighting the continued threats facing the species.