Headstarting Gopher Frogs from the Croatan National Forest
Gopher frogs Rana capito are listed in North Carolina as endangered and are being considered for listing under the federal Endangered Species Act. Only 7 of 23 historical populations of this species currently remain in a few ponds scattered in the Coastal Plain. Several of these ponds are in the Croatan National Forest, and I partner with the North Carolina Wildlife Resources Commission to headstart frogs from this population.
What is Headstarting?
Egg masses are labelled and carefully transported back to the lab at CMAST. Small samples are also collected for genetic analysis to help discern the structure of the remaining gopher frog populations in North Carolina.
In late winter, small portions of gopher frog egg masses are collected and tended indoors for several weeks. Soon after hatching into tadpoles, they are moved into outdoor mesocosms (enclosed ecosystems with natural pond conditions) filled with rainwater at Carteret Community College. The floor of each mesocosm is covered with maidencane, a plant which helps maintain water quality and provides shelter. The tadpoles are fed nutritious algal wafers and forage on natural food items growing in the mesocosms.
Tadpoles are checked daily to monitor health, growth and development. After metamorphosis, the froglets—each weighing about 7 grams—are ready for release. Froglets are carefully returned to the same pond where they came from. Releases occur just before dark to avoid predators and the direct heat of the sun.
Similar headstart efforts are underway at the North Carolina Aquarium at Fort Fisher and the North Carolina Zoo. Over 3000 froglets have been released since 2011. Additionally, the North Carolina Aquariums support analysis of the gopher frog populations’ genetic structure which is being conducted at the University of North Carolina Wilmington. Together, these projects support the Wildlife Resources Commission comprehensive strategy to conserve and enhance gopher frogs in the state.
It takes a keen eye to spot gopher frog egg masses. The southern leopard frog lays its eggs around the same time. Size and color of the egg masses help experts distinguish between the two species.
Jeff Hall (left) is a herpetologist with the North Carolina Wildlife Resources Commission. He and his assistant, Myles Lance (right) survey ponds throughout the coastal plain to find gopher frog egg masses. A conservation plan for gopher frogs and detailed protocols for rearing them are essential for keeping all the partners on the project aligned.
Ben Ingham (S@C 2020) adds dried maidencane to the outdoor mesocosms. Each mesocosms is filled with about 250 gallons of rainwater. Standpipes prevent tanks from overflowing in heavy rain events. Screens over the tops keep tadpoles safe from predators like insects or birds.
Nora Skinner (S@C 2019) holds the first froglet headstarted at CMAST and Carteret Community College just before release. We had to hike in over a mile through the rain, but it was worth it to see the frogs hop away! Every froglet is injected with a small bit of dye prior to release to allow us to identify them as a headstarted frog should we ever encounter them again.
At release, froglets weigh about 7 grams. They face many threats as they move away from the ponds into the forest uplands. Once on land the frogs find a stump hole to use as a burrow. In other parts of their range further south, gopher frogs use holes dug by gopher tortoises, which is how they got their name.
Jeff Hall holds a rare find – an adult gopher frog getting ready to find a mate at a pond in the Croatan National Forest. These frogs spend most of their lives underground. In late winter, they emerge and make their way to a pond, which could be up to 5 km away.