SCCF ‘scoping out’ gopher tortoise burrows
The Sanibel-Captiva Conservation Foundation’s (SCCF) Wildlife & Habitat Management team has begun its annual gopher tortoise burrow surveys with a new method this year — video scoping.
“Using an endoscope camera attached to a PVC pole, the insides of a gopher tortoise burrow can be visualized,” SCCF wildlife biologist Mike Mills said on Nov. 26. “Usual signs of activity include tortoise tracks going in and out of the burrow, the ‘mouth’ of the burrow having a well-defined, half-moon shape, and a tidy burrow entrance with little to no natural debris.”
However, basing the burrow activity status on these characteristics alone may not always be totally accurate.
“That’s where burrow scoping comes in. The camera gives us a better picture of what is going on inside the burrow. This technique allows for higher accuracy in determining if a burrow is being actively used or not,” he said.
It also can provide information on what other animals are utilizing the burrows, such as frogs and insects. With recent hurricanes and storm surge events affecting Sanibel’s gopher tortoise population more than ever before, the data can provide crucial insight for its conservation.
Mills recently presented the SCCF’s research on the effects of hurricanes on Sanibel’s gopher tortoise population at the 46th annual Gopher Tortoise Council Meeting in St. Petersburg. It allowed the research to be shared with gopher tortoise scientists from around the southeast United States.
The SCCF has been conducting annual gopher tortoise burrow surveys on Sanibel preserves since 2000. The Frannie’s Preserve and C. R. Johnston Tract surveys began in 2000, while the Dayton Preserve, Walker Preserve and Wulfert Gopher Tortoise Preserve began in 2007.
The average active burrow percentages across all five preserves stayed relatively consistent between the years 2007-21, with a 12.1% increase of active burrows overall. However, Hurricane Ian in September of 2022 changed that consistency with a loss of 59.2% active burrows.
“In 2023, total active burrows increased by 9.4%, showing this species’ resiliency in the face of destruction,” Mills said. “Being such a long-term studied population, SCCF’s gopher tortoise research can provide a base model for other coastal or insular gopher tortoise populations around the southeast region that may be affected similarly by storms currently and in the future.”