"Right now, we just wait and hope they survive and flourish."
John Jensen, Georgia DNR
By Christine Griffiths
At least, that's the hope of biologists who are conducting a five-year experiment at The Nature Conservancy’s Williams Bluffs Preserve in southwest Georgia. They're aiming to increase populations of this stout-bodied amphibian, which was once common throughout Georgia and the rest of the Southeastern Coastal Plain but is now found in fewer than 10 sites in the state.
A Species Under Siege
Only two to four inches long, adult gopher frogs are found in the longleaf pine ecosystem of North America's Southeastern Coastal Plain. The species range stretches from North Carolina through Florida and west to southern Alabama.
The frogs spend most of their time in burrows — often those made by the gopher tortoise, another imperiled species. But gopher frogs breed and grow up in shallow, fishless and often ephermeral wetlands embedded within those longleaf forests, making them especially vulnerable to human activity.
The destruction and alteration of their habitats have caused gopher frog populations to decline drastically throughout the Coastal Plain. Specific factors include:
- The stocking of fish in wetlands where the gopher frog breeds;
- Wetland draining;
- The decline of gopher tortoises; and
- A lack of natural and prescribed fires in longleaf pine forests.
Gopher Frogs Get Second Chance
With temperatures hovering near 100 degrees, scientists from the Conservancy, the Georgia Department of Natural Resources (DNR) and the Atlanta Botanical Garden gathered in August 2007 amid the longleaf pine forest and dried limesink wetlands at Williams Bluffs Preserve to introduce an experimental population of gopher frogs.
Sixty-eight tadpoles and four newly-metamorphosed frogs were released in a man-made pond at the preserve. Collected as eggs from the wild at the Jones Ecological Research Center in Baker County, Georgia, the tadpoles and frogs were nurtured at the Atlanta Botanical Garden in preparation for the release.
Typically, the preserve’s ephemeral ponds would have been the ideal habitat for the species, but this year’s drought left the natural ponds too dry. Still, scientists declared the preserve "the best suitable habitat currently without gopher frogs."
“We built a shallow pond next to the natural wetland area and planted aquatic vegetation to create a structurally diverse habitat for the tadpoles and frogs to live and hide among,” says Malcolm Hodges, an ecologist with The Nature Conservancy in Georgia.
And They Glow!
Before they were released, John Jensen of the Georgia DNR injected all four metamorphosed frogs and many of the legged tadpoles with a small amount of fluorescent elastomer under the skin of the thighs.
Harmless to the critters, this bright orange substance illuminates under black light, allowing biologists to monitor the progress of these individuals as they continue to grow and breed.
“We will continue with similar releases for a minimum of five years, while continuing to monitor the progress of the frogs and their breeding success,” said Jensen. “Right now, we just wait and hope they survive and flourish.”