A tiny species of poison dart frog barely the size of a human fingernail has been discovered in a pocket of forest in central Panama, but its unique chirps may not be heard for much longer.

The new species—dubbed Andinobates geminisae—was discovered in 2011 by researchers from the Smithsonian Tropical Research Institute and the Autonomous University of Chiriquí, and described last month in a paper in the journal Zootaxa. It has bright orange skin with a pale marbling on its underside; its vocalizations are made of up of pulses, or "clicks," at wavelengths below those of other frogs in its genus. (You can hear the frog's calls recorded against the flowing water of the Rio Caño here.)

The new frog was actually hidden in plain sight for many years; researchers thought it might have just been a color variation on a frog from another genus, the strawberry poison dart frog (Oophaga pumilio). That frog is similarly small and orange but much more common, with a range that extends through Panama, Nicaragua and Costa Rica. But Smithsonian herpetologist Cesar Jaramillo suspected that one of these frogs was not like the other: He noted morphological differences between the adults and tadpoles of the two types of frogs and thought they might be separate species. DNA tests conducted at the University of Los Andes in Colombia later confirmed this. The new species was placed in the genus Andinobates. The genus itself was only identified three years ago (the frogs had previously been lumped in with another genus) and now has 15 known species. A. geminisae joins another new species, A. cassidyhornae, which was discovered in Colombia last year.

Unfortunately, the researchers warn, A. geminisae only lives in a very small area in Panama's Donoso District and should be considered threatened. Donoso has been heavily deforested in recent years to make way for gold, silver and copper mines, some of which operate illegally. The researchers wrote that additional studies of this new species are "urgently needed" to determine its ecology, breeding biology and other behaviors so we can understand how to save it while there is still time.

Photo: Cesar Jaramillo, courtesy of the Smithsonian Tropical Research Institute