Displaced Gopher Tortoises Might Survive On Islands, Say UF Researchers

by Tom Nordlie (352) 392-1773 x 278
August 4, 2005

ST. AUGUSTINE, Fla. --- The gopher tortoise, a burrowing reptile unique to the U.S. Southeast, is gradually disappearing because the dry, sandy upland where it commonly dwells is ideal for evelopment. But University of Florida researchers say the tortoise’s ability to survive in coastal areas may be one key to future preservation efforts.

A UF study of gopher tortoises on small islands near St. Augustine could reveal whether displaced colonies can be successfully relocated to similar sites in Florida and other states, said Dana Ehret, a doctoral student with UF’s Institute of Food and Agricultural Sciences.

“Not much is known about gopher tortoise populations on small islands, because researchers have pretty much overlooked them,” Ehret said. “For example, we don’t know how common these populations are, how the tortoises cope with the constant exposure to salt or how they manage to keep their burrows from being flooded by the higher water table.”

Gopher tortoise burrows are a familiar sight in rural inland areas from Louisiana to South Carolina, the tortoise’s native range, he said. Marked by piles of sand at their entrances, the burrows can be 10 feet deep and 40 feet long. More than 360 other species use the burrows for shelter.

The tortoises are protected by Florida law and developers have several options when specimens are found in areas slated for construction, Ehret said. They can build at a distance from burrows, move tortoises to other parts of the same property, relocate tortoises to distant properties or obtain permits allowing work to proceed in exchange for financial support of tortoise conservation.

The latter option preserves tortoises and habitat elsewhere, but animals on the development site are often lost when burrows collapse, he said.

Developers often prefer to obtain the permits due to time constraints, Ehret said. Some tortoise experts consider the permits an acceptable — though not ideal — option, and believe present relocation efforts have not succeeded as a conservation measure.

“Relocation sounds like a great idea, but in practice it’s had problems,” Ehret said. “For developers, there’s a lot of work involved in capturing tortoises and arranging for them to be placed on other property. Researchers are concerned that if the new habitat isn’t just right the tortoises will leave, and may end up injured or killed anyway.”

Another drawback to current relocation efforts is that tortoises placed on privately owned land could be displaced again by future development, said Mike Moulton, a UF associate professor of wildlife ecology and conservation and Ehret’s faculty adviser. The UF researchers believe a better option may be to relocate tortoises on small islands likely to remain undeveloped, either due to government protection or simply because they are unsuitable for development.

The UF study focuses on gopher tortoise populations on five small islands in the Atlantic Intracoastal Waterway, he said. Despite the reptiles’ size — up to 15 pounds — and ponderous appearance, they float and are sometimes observed swimming.

Hundreds of islands are found throughout the waterway, which is a series of bays, estuaries and navigation channels reaching from Miami, Fla. to Norfolk, Va., Moulton said. Other islands along the Atlantic and Gulf coasts might also be suitable as tortoise habitat.

“We hope that with the right preparation, some of these islands could serve as homes for gopher tortoises and possibly for beach mice, indigo snakes and other species impacted by development,” he said. “It might be possible to construct new islands specifically for this purpose.”

This fall, Ehret will help monitor an experimental effort to relocate Florida gopher tortoises to an island home. A Flagler County developer has worked with state agencies for several years to arrange the relocation, which is aimed at establishing a permanent tortoise refuge, Ehret said.

“Just by coincidence, this project had been developing independently of our UF research and I jumped at the chance to get involved,” Ehret said. “By observing newly introduced tortoises in a coastal habitat we may learn things that help us focus our own research.”

Gopher tortoise management efforts need to be stepped up throughout the Southeast, said Craig Guyer, a biological sciences professor at Auburn University in Auburn, Ala. Loss of habitat is the most serious threat facing gopher tortoise populations in all six states where the animal is found.

“Florida is 10 years ahead of everyone else in terms of bumping into this problem and being forced to come up with solutions,” Guyer said. “The idea of setting aside land for permanent gopher tortoise habitat is catching on here in Alabama and I’ll be interested to see if that proves viable in coastal areas in Florida.”

 

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Mike Moulton, an associate professor with the University of Florida’s Institute of Food and Agricultural Sciences, checks a gopher tortoise burrow in Gainesville — Thursday, Aug. 4, 2005. Moulton is studying whether gopher tortoises displaced by inland development could be relocated to coastal islands protected from development. Found only in six Southeastern states, the reptiles are disappearing due to loss of habitat. (AP photo/University of Florida/IFAS/Thomas Wright)