Camryn M. Kiel

EFFECTS OF PRESCRIBED FIRE ON THE TEXAS TORTOISE (GOHPERUS BERLANDIERI)

Prescribed fire has become a popular land management tool to create variety in vegetation, which may benefit wildlife species that utilize multiple cover types. One such wildlife species is the state-threatened Texas tortoise (Gopherus berlandieri), a slow-moving, long-lived ectotherm in southern Texas. The body of literature examining the effects of fire on herpetofauna is growing; however, we found no such data for Texas tortoises. This study assesses the vegetation tortoises use in southern Texas coastal rangelands, as well as the effects of prescribed fire on their movement, thermal ecology, and survival through fires. On the East Foundation’s El Sauz Ranch in Willacy County, we affixed tortoises with GPS loggers, radio transmitters, and temperature loggers to monitor these variables through prescribed fires from 2022-2024. This property employs a prescribed fire regime with pastures assigned to summer burns, winter burns, or no burns (control) at varying burn frequencies. We also monitored tortoises before and after fires to quantify fire-induced mortality. We collected data across seasons to determine if the season of fire plays a role. Preliminary analyses show that Texas tortoises use a variety of vegetation types throughout the year, which denotes the importance of heterogeneity for their conservation. Additionally, winter fires may also have a lower risk of fire-caused mortality. This study was designed to inform land managers of prescribed fire practices that mitigate tortoise mortality through maintaining vegetation structure that suits their activity and thermal needs.