Glass Frogs: Centrolenidae

Of the 134 species in this family, the World Conservation Union (IUCN) considers sixty to be at risk, and another forty-nine to be Data Deficient, which means too little information is available to make a judgment about the threat of extinction. Of the sixty at-risk species, six are Critically Endangered and face an extremely high risk of extinction in the wild. These include Centrolene ballux, Centrolene gemmatum, Centrolene heloderma, Centrolene puyoense, Cochranella anomala, and Hyalinobatrachium crybetes. Many of the glass frogs are little known and have no common names in the English language. Two of these, Centrolene ballux and Centrolene heloderma, have lost eighty percent of their total number in a very short time. Centrolene ballux, which lives in Colombia and Ecuador, has become very rare in both countries and has not been seen at all in Ecuador since 1989. Centrolene heloderma also lives in Ecuador and Colombia, but has not been seen in Ecuador since 1979. The disappearance of both frogs may be tied to global warming. As the temperatures have changed, the sky is no longer as cloudy as it once was in the frog's habitat. Without the clouds, the weather may be becoming too dry for the frogs. In addition, people are cutting down the frog's forests to build homes, create farms, or to take the logs, and fires are also destroying the forest.

The other four Critically Endangered glass frogs live in very small areas. One makes its home in Honduras, and the other three in Ecuador. In each case, the frog's forest has been destroyed for purposes as farming or logging. The forests where the only known population of Centrolene puyoense lived, for example, was cut down and the land cleared out in 1996.

Besides the Critically Endangered species, sixteen are Endangered and face a very high risk of extinction in the wild, twenty-nine are Vulnerable and face a high risk of extinction in the wild, and nine are Near Threatened and at risk of becoming threatened with extinction in the future. Habitat loss and possibly infection with a fungus, called chytrid (KIT-rid) fungus, are likely causing many of the problems for these frogs. Others appear to be quite rare, but scientists are unsure about how many individuals actually live in the wild. The glass frogs are difficult to spot at night when they are active and during the day when they sit still on leaves. In addition, many of the species spend almost all of their time high up in trees and other hard-to-reach spots. An example is the species known by its scientific name of Cochranella luminosa. This glass frog is found on the western side of the Andes Mountains in Colombia, where it lives at the tops of trees. Recently, however, scientists have begun studying the tops of trees, called a forest's canopy (CAN-oh-pee), using ropes and tall platforms. With these new methods, they will likely learn much more about tree-living frogs, as well as other species of plants and animals.