Carolina Gopher Frog
By Laurie Walden, SC Master Naturalist & Palmetto Pro Birder
An elusive frog that spends most of its life underground is on the minds of researchers at the S.C. Department of Natural Resources (SCDNR). The Carolina gopher frog (Rana [Lithobates] capito capito) has been listed by the State of South Carolina as an endangered species, but studying the frog has been a challenge because of its secretive habits.
“We are seeking a better understanding of the Carolina gopher frog,” says SCDNR herpetologist Will Dillman. However, the frog is difficult to detect, he says, as it lives underground during the day and emerges at night only to eat, or to breed in springtime.
Another challenge for researchers is the Carolina gopher frog’s declining habitat and its special needs. It depends on fire-maintained, longleaf pine-wiregrass ecosystems for most of its needs, but during breeding season, it needs seasonal, isolated wetlands without predatory fish. The frog used to be more common in the state’s Coastal Plain and Sandhills. However, with the decline of longleaf pine habitats, the frog decreased also. In South Carolina, the frogs are found only on a few public properties: the Savannah River Site, the Francis Marion National Forest, and the Santee Coastal Reserve.
SCDNR, as part of the Natural Heritage Program, has designated the Carolina Gopher frog as one of the agency’s “highest priority” species. Besides studying the frog, researchers have tried to relocate the frog, but efforts to relocate historic breeding ponds outside of the public lands have had little success. SCDNR also is investigating where the Carolina gopher frogs used to live in our state.
The Carolina gopher frog, along with the Florida gopher frog, are subspecies of the gopher frog (Rana [Lithobates] capito). Gopher frogs are plump, medium-sized frogs with large heads and short legs. They are 2 to 4 inches in size. They have dark brown, irregular spots on a creamy, gray or brown-colored body, with yellow-orange hidden on their thighs and groins. They resemble toads because they are covered with warts. They also have ridges along the sides of their bodies.
They can live up to six or seven years, but most of their lives are spent underground, in holes left by gopher tortoises, (hence its name, gopher frog). If gopher tortoise holes are not available, they will inhabit holes made by rodents or crayfish, as well as a stump holes and root tunnels. Each frog has an individual burrow. During nighttime, each frog emerges from his or her hole to feed. The frogs sit outside their holes, on little perches, or “platforms,” of cleared vegetation, from which they ambush prey, such as, beetles, crickets, spiders and other invertebrates. They also will eat small frogs and toads, sometimes swallowing them whole with their large mouths.
After late winter or early spring rains, anytime between February and April, the frogs will travel up to a mile to find an isolated ephemeral pond or other wetlands site. Often the male frogs will call their mates underwater, making a vibrating, guttural sound resembling an old man snoring. After they mate, females will deposit large egg masses, of up to 2,000 eggs, underwater. Many of the eggs are eaten by aquatic insects such as caddish fly larvae and salamanders. The tadpole stage lasts from four to seven months. Tadpoles and frogs will face threats from banded water snakes, turtles, raccoons, hawks and owls. When the frogs are threatened, they will lower their head, and cover their eyes with their front feet, looking as if they are playing peek-a-boo.
While the Carolina gopher frog is listed as endangered by the State of South Carolina, it is merely listed as “at risk” by the U.S. Fish and Wildlife Service. “At risk” is not an official listing. The Carolina gopher frog can also be found in North Carolina and Georgia. A related species is the dusky gopher frog (Rana [Lithobates] servosus), also known as the Mississippi gopher frog, which was considered a subspecies of the gopher frog until 2001, when genetic evidence elevated it to full species status. The dusky gopher frog has been listed by the U.S. Fish and Wildlife Service as an endangered species.