Greenhouse Frog – Beaufort County – © Jake Zadik
Description: The Greenhouse Frog is a very small frog, rarely achieving total lengths over an inch. They are typically mottled brown in color and may have two light stripes extending down the back from behind the eyes to the start of the rear legs. The belly is paler and less patterned than the dorsum. The feet lack webbing and the rear legs may have a series of dark bands. Juveniles are smaller versions of the adults.
Natural History: The Greenhouse Frog is a nonnative species in the state of South Carolina. Unlike all of our native frogs, this frog does not have a tadpole stage. Instead, males will call on moist nights in late winter, early spring, and mating occurs on land. Females will typically lay their eggs on land, under forest floor debris. One to two dozen eggs are laid, and the larvae fully develop inside the eggs and hatch as a fully formed frog.
The Greenhouse frog is is completely terrestrial and found in moist forest areas or home gardens. The are most active during the night and eat almost any small invertebrates they can fit in their mouth. Many native predators have been known to feed on these frogs such as small snakes, larger amphibians, birds, and likely small mammals.
Similar Species: Cricket Frogs (Acris sp.) are a similar size and have a similar body shape. However, the light striping on the Cricket Frogs generally forms a “Y” shape, while the greenhouse frog will have parallel stripes. The greenhouse frog also lacks webbing between its toes. The Eastern Narrow-mouthed Toad (Gastrophryne carolinensis) can also be a similar size, but are generally much chunkier in appearance.
Distribution: The Greenhouse Frog is native to Cuba, the Bahamas, and other areas of the Caribbean. They have been present in Florida since the late 1800s and have slowly spread throughout the Southeast, typically hitching a ride on transported plants (hence their common name). They were first found in South Carolina in 2015 in the Charleston area. They have continued to spread and show up throughout coastal areas of our state.
Notes: While they currently pose little threat to native species, there is concern that this nonnative species compete with native species for food resources. The South Carolina DNR and other organizations are interested in monitoring the spread of this species throughout the state. If you encounter this frog, please consider sharing the location through citizen science projects such as HerpMapper or iNaturalist.
Contributed by Jake Zadik (2/17/2023)