The Rabbs’ Fringe-limbed Treefrog, Ecnomiohyla rabborum, is listed as ‘Critically Endangered’ on the IUCN Red List of Threatened Species. Its small range is in the mountains around El Valle de Anton in Central Panama. It is possibly endemic to this area. This treefrog lives in the forest canopy, and is known for using its extensive toe webbing to glide from tree to tree.

The Rabbs’ Fringe-limbed Treefrog is named after two people, Dr. George Rabb, a previous chairman of the IUCN Species Survival Commission and the former director of the Brookfield Zoo in Chicago, Illinois, and Mary Rabb, who was a biology teacher and past librarian at Brookfield Zoo. The naming of this frog is in recognition of George and Mary Rabb for their contributions to conservation, and for their major support of amphibian conservation programs around the world.

The main threat to Rabbs’ Fringe-limbed Treefrog is thought to be the chytrid fungus, Batrachochytrium dendrobatidis. Since this fungus was found in the area in 2006, the population has declined and only one individual has been heard in the wild since. Another threat is sprawling development of El Valle.

Individuals were taken for captive breeding at the El Valle Amphibian Conservation Center, in El Valle de Anton, Panama, but reproduction has not yet been successful. There are continuous field surveys in the area, but the last observation of Rabbs’ Fringe-limbed Treefrog in the wild was a call heard in 2007.