Artificial snake hibernacula provide suitable microclimate but are not immediately adopted

Artificial snake hibernacula (ASHs) are an increasingly popular tool to replace lost habitat. However, no published work has compared the overwinter thermal characteristics of these constructs with those experienced by snakes in nearby natural hibernacula. Following a disturbance, we used the establishment of two ASHs to evaluate the structures' ability to buffer external conditions, match the thermal needs of Great Basin Gophersnakes (Pituophis catenifer deserticola), and monitor adoption in the main hibernaculum by the original cohort of displaced snakes and broader community (gophersnakes, Western Yellow-bellied Racers (Coluber constrictor mormon), and Western Rattlesnakes (Crotalus oreganus oreganus)). Microclimate loggers inside the ASHs showed the structures buffered against external temperature and humidity conditions. Snowfall did not influence the internal temperatures. Surgically-implanted transmitters indicated the body temperatures of hibernating gophersnakes within the main artificial hibernaculum were comparable to those using natural hibernacula. The ASHs provided thermal microsites that mirrored gophersnake hibernation patterns at depths of 2.6-3.1 m. Despite extensive mitigation, only six of 93 displaced snakes were found to have overwintered in the main artificial hibernaculum in the first year, and none were found to have returned two years post-disturbance (though two newly identified snakes overwintered in the second year). We conclude that ASHs can be built conducive to snake survival, but future designs should consider species-specific and locational requirements. Temperature profiles should be collected from all ASHs to assess their viability in varied and extreme environments. We caution against routine use of this mitigation tool without additional research assessing the long-term adoption.