Researchers from the Zurich Zoo said they are working to save orange-eyed tree frogs, as they face a threat from a fungus.

The nocturnal frogs are native to Costa Rica's tropical forests, preferring moist lower tree levels.

But the species is endangered and already extinct in large parts of its range, with the biggest threat being the chytrid fungus.

Footage shows the rare frogs living in conservation shelters built by the team at the zoo in Switzerland.

Experts said the deadly pathogen infects amphibians' skin, thickening it and disrupting vital functions like water absorption, breathing, and thermoregulation.

The infection almost always proves fatal.

They added that the chytrid fungus likely originated in Asia and spread globally in the 1980s. It is now considered one of the greatest threats to amphibians worldwide.

The zoo coordinates conservation, research, and education to fight amphibian decline as 41 percent of the species are threatened with extinction.