Web-Footed Coqui

Web-footed Coqui, Puerto Rican Stream Coqui, Karl’s Robber Frog (Eng.), Coqui Palmeado (Sp.), Eleutherodactylus karlschmidti (Sci.), endemic resident, Puerto Rico.

Photo The Amphibians and Reptiles of Puerto Rico, Juan A. Rivero. Information compiled by Alan Mowbray, Interpretive Media Writer, EYNF/LEF

General Information

Taxonomy: Class-Amphibia, Order-Anura, Family-Leptodactylidae, Genus-Eleutherodactylus, Species-E. karlschmidti. There are 16 species of Eleutherodactylus frogs on the island of Puerto Rico. Most, but not all Eleutherodactylus frogs have individual (non-webbed) toes. Eleutherodactylus frogs do not pass through a tadpole stage, and thus do not require water as a part of the reproduction process. Instead, after fertilization by the male, eggs are laid by the female in humid areas. When the eggs are hatched, a fully formed froglet (a tiny replica of the adult frog) emerges. In Puerto Rico, all Eleutherodactylus frogs are commonly known as coqui frogs, although the males of only two of the 16 known Puerto Rican species emits the  Ko-Kee call.

Description

The Web-footed Coqui (E. karlschmidti) is the largest of the local Eleutherodactylus species, typically measuring 2 to 3.5 inches (50 to 80 millimeters) snout to vent length. The color is black or gray, with yellowish mottled spots which are larger on the flanks than on the dorsum. A narrow, light colored line crosses the forehead between the upper eyelids. The ventral area is grey and yellowish-white. E. karlschmidti has very large eyes, and is the only coqui species that has extensively webbed toes. It is unique among members of the genus in having a bi-lobal vocal sac, extending from the tip of the jaw to the base of the throat.

Habits

Very little is known about the life history of this species. It feeds mostly on insects, apparently preferring flies and mosquitoes. Arachnids, centipedes, crustaceans, millipedes and mollusks may also be part of its diet. E. karlschmidti’s call is loud and sonorous (Click here), seeming even louder when echoing off of rocks and boulders near its mountain stream habitat.

Habitat

The Web-footed Coqui is thought to inhabit rocks and boulders near mountain streams. Unfortunately, E. karlschmidti seems to have disappeared from the forest in the last two decades, and little if anything is known about the reasons for its disappearance. It is possible that they lay their eggs near flowing streams and they are carried away by flood waters. Rats have been known to be attracted to the calling sounds of the male, but these are certainly not the only factors responsible for this animal apparent extinction.

Where to look for this animal in the EYNF

During nighttime hours on rocks and boulders near flowing streams above 1300 feet (400 meters).

Note: Since this animal is presumed to be extinct or close to extinction, any sightings should be recorded and reported to the Forest Service!