Corquin Robber Frog

Honduran frog species with a small range

The Corquin robber frog lived in the constantly misty and humid montane rainforest, at an elevation of 1,400 to 1,840 meters above sea level, in Montaña de Celaque National Park in western Honduras. Its former range in the Cordillera de Celaque mountain range, where it was sighted in only two places, is estimated at 97 square kilometers. The IUCN lists the Corquin robber frog as extinct, because the two last confirmed sightings occurred in 1987 and 1990.

Despite numerous extensive searches over the years, scientists were unable to locate the Corquin robber frog again. They searched not only at the sites where the frog had been sighted, but also in adjacent areas with suitable elevation and suitable habitat.

The biologist Josiah Townsend rules out the possibility that its range may have been larger after all. Between the sites in the Cordillera de Celaque where it was found and the nearest mountain, there is a large area whose elevation and natural conditions are not suitable as habitat for the species. The ground-dwelling frog species preferred lower mountain regions along streams in humid deciduous forest.

Corquin robber frog – Fact Sheet

scientific names	Craugastor anciano, Eleutherodactylus anciano
original range	Honduras
time of extinction	1990
causes of extinction	habitat loss, fungal disease, landslides, water pollution

Corquin robber frog: first scientifically described shortly before its extinction

The holotype—the specimen on which the species was first scientifically described—was found in El Chagüitón at an elevation of 1,830 meters. The site lies about 19 kilometers southeast of the city of Corquín in the Cordillera de Celaque. The adult male frog was discovered by the biologists James R. McCranie and Larry David Wilson in May 1980. Adult female frogs served as paratypes, which help in the scientific identification of a species.

Eight years later, McCranie, Wilson and the herpetologist Jay M. Savage described the new frog species as Eleutherodactylus anciano. The scientists explain how the name came about in their first description (1988):  A nciano (Spanish for old) is an allusion to the reptile and amphibian researcher Kenneth L. Williams. He materially supported Wilson and McCranie in describing the Honduran herpetofauna and helped collect the paratypes. Williams’ nickname was also El anciano.

In 1989, McCranie, Savage and Wilson also provided the first scientific description of McCranie’s robber frog, which is native to Honduras and is now also considered extinct. 

The description of the new amphibian species shows that male Corquin robber frogs, at 3.3 centimeters in body length, were smaller than the females. Females could reach up to 4.2 centimeters in length.

Habitat destruction: Already extremely rare when discovered

As early as 1988, when McCranie, Savage and Wilson described the robber frog, the animals were rare. The scientists collected all specimens along a small stream that ran between two heavily deforested hillsides used as pastureland. The vegetation preferred by the Corquin robber frog existed in this region only on isolated mountain peaks.

The populations of frog species belonging to the so-called Craugastor-rugulosus group, including McCranie’s robber frog, declined dramatically throughout Honduras between the mid-1980s and the early 1990s. This happened not only in areas marked by habitat destruction, but also in natural regions, according to the IUCN. This can be seen as an indicator that the fungal disease chytridiomycosis played a role in the amphibians’ deaths.

Experts assume that fungal disease was not the only factor contributing to the disappearance of the Corquin robber frog. The loss of habitat for the creation of agricultural land, deforestation, forest fires, water pollution and landslides also led to its extinction.

Almost half of all amphibians in Honduras are critically endangered or extinct

In their report The Conservation Status of the Herpetofauna of Honduras (2003), McCranie and Wilson examine amphibians and reptiles in Honduras and the threats they face from humans. Among other things, they note that there are no longer any amphibians or reptiles there that exist in their natural habitat entirely without human interference. The reasons lie in the uncontrolled growth of the human population, the loss of natural habitat, environmental pollution, diseases and epidemics, hunting and the exploitation of nature.

In their study, Wilson and McCranie reveal that 48.8% of the endemic amphibian species in Honduras are already extinct or have steadily declining populations. In addition, 27% of the reptile species native only to Honduras show declining population numbers. The assessment also shows that among the amphibians endemic to Honduras, eight species are most likely extinct.

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