Frog of the Week

River Frog (Rana heckscheri)

River Frog
photo from the USGS
least concern

Common Name: River Frog
Scientific Name: Rana heckscheri
Family: Ranidae – True Frog family
Locations: United States – Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina
Introduced Location: China
Male Size: 3.5 – 4.7 inches (90 – 120 mm)
Female Size: 5.1 – 6  inches (90 – 155 mm)

The River Frog is found in the southeast United States but has slowly disappearing along the edges of the range, including totally from North Carolina and Alabama. They haven’t been seen in North Carolina since 1975. The main reason for the decline is believed to be from habitat loss. The International Union for the Conservation of Nature (IUCN) Red List still lists them as Least Concern though. They are a nocturnal species, mostly being found at night.

The River Frog produces toxins that are harmful to some predators including Indigo Snakes (Drymarchon) and Water Snakes (Nerodia). After eating the frog, these predators will throw up the frog and then wipe its mouth on the ground afterwords. They seem to be harmless to humans and are relatively easy to catch compared to other frogs. I wouldn’t try eating them though.

River Frog
photo by Todd Pierson


Breeding for the frog takes place from April to August, if conditions are right. They mate in permanent bodies of water due to tadpoles taking over a year to undergo metamorphosis. The males will come to the water and start calling. Once the females arrive, the male will grasp them from behind in the amplexus pose. After, the female will lay her eggs and the male will then fertilize them. Th female can lay between 6000 – 8000 eggs at a time. The eggs hatch between 3 – 15 days. The tadpoles will remain active during winter and will generally complete their metamorphism in the spring. Tadpoles can take over 2 years to complete their metamorphism.

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