Locust Coqui

Photo of the Locust Coqui/Coquí Martillito

Locust Coqui, Warty Coqui, Puerto Rico Small-eared Frog (Eng.), Coqui Martillito (Sp.), Eleutherodactylus locustus (Sci.) endemic species, Puerto Rico.

Photo Luis J. Villanueva-Rivera. Information compiled by Alan Mowbray, Interpretive Media Writer, EYNF/LEF

General Information

Class-Amphibia, Order-Anura, Family-Leptodactylidae, Genus-Eleutherodactylus. Species-E. locustus. IUCN (Red List) status – critically endangered (CR). E. locustus has suffered a population decline of more than 80% due to introduced predators and amphibian chytrid disease. Scientists believe that amphibian chytrid may be exacerbated by climate change – warmer temperatures dry moist habitats, causing stress that may lead to greater susceptibility to the disease.


The Locust Coqui is a small species, approximately 0.78 inches (20 millimeters) in snout to vent length. It is brown overall, minutely variegated with lighter brown or cream colors. A pair of externally concave lines is almost always visible on the back, but a variable width line along the vertebrae may or may not be present. The eyes are large and protuberant, and the angles at the side of the snout are rounded and indistinct.


Like other Eleutherodactylidae, E. locustus does not have inter-digital membranes and so is not well adapted to swimming; instead, it has pads on its toes that allow it to adhere to leaves and branches. The species utilizes internal fertilization - the fertilized eggs undergo direct development. The tadpole stage occurs entirely within the egg, rather than as a free-living larva. Thus, a tiny but fully functional froglet hatches directly from the egg. E. locustus females deposit four to six clutches of about 28 eggs each per year, mostly during the rainy season, with a development period of 26 days. Males guard the eggs to keep them moist and remain in the nest for a few days after they emerge. The voice of E. Locustus is a short whistle, followed by a series of clicks (Click here to hear recording).


The Locust Coqui is restricted to the interior uplands of eastern Puerto Rico at elevations of 895 to 3,444 feet (273 to 1,050meters) above sea level. A terrestrial species, it occurs in mesic broadleaf subtropical moist lowland or subtropical moist montane forests.

Where to look for this animal in the EYNF

Because there has been an unexplained major decline in the abundance of this species in the last two decades, even in relatively undisturbed forests (such as El Yunque) this animal is rarely seen. However, there is an easily accessible Forest location that sustains an E. Locustus population. On the fern-covered slope above the Big Tree Nature Trail’s roadside parking lot, the calls of Locust Coquis can be heard beginning in the late afternoon hour, just before sunset.

Additional Information

USDA Forest Service
El Yunque National Forest
HC-01 Box 13490
Rio Grande, PR 00745
787 888 1810


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