Two frog species feared extinct by scientists have been rediscovered in Colombia, renewing hope among conservationists trying to save amphibians.

For the first time in 14 years, the critically endangered Santa Marta harlequin frog (Atelopus laetissimus ) and San Lorenzo harlequin frog (Atelopus nahumae) were spotted in a nature reserve on the Caribbean coast of Colombia.

San Lorenzo harlequin frog, Atelopus nahumae, Colombia.
(Courtesy of Juan Manuel Renjifo)

A deadly fungus is decimating frog populations in Central and South America by smothering amphibian skin, but the two species appear to be unscathed.

"It's a race against time to prevent chytridiomycosis from wiping out amphibian populations, but now we have discovered what appear to be healthy populations of these endangered species," Claude Gascon, vice-president for regional programs at Conservation International, said in a statement Tuesday.

The fungus has been found as close as 40 kilometres away, on the other side of the Sierra Nevada mountains.

Santa Marta harlequin frog, Atelopus laetissimus, Colombia.
(Courtesy of Juan Manuel Renjifo)

Other species are in the El Dorado Nature Reserve, including:

• Five threatened amphibians found nowhere else.
• The endangered Santa Marta parakeet.
• Neotropical birds that breed in Canada and the U.S., such as the cerulean and the golden-winged warbler.

Frogs and other amphibians also face pressure from pollution, climate change, deforestation and urban sprawl.

The animals are exposed to more threats since they live on land and in water.

Last year, the Alliance for Zero Extinction, a group of conservationists, said preserving 595 sites around the world could help save 794 endangered species.