Forty percent of all the frogs in the world are in danger of extinction, according to the Smithsonian Institution. Pollution, pesticides, climate change and now a fungus are taking a toll on this diverse group of amphibians. Until recently, the central rain forest of Panama was rich in frog species. Smithsonian conservationist Brian Gratwicke is directing a campaign to save and reproduce in captivity some of the world's most endangered frogs.

Sierra Llorona is a tropical rainforest in Central Panama. It's rich in all sorts of flora and fauna, especially frogs.

That's what Brian Gratwicke and his team are looking for. He works for the Smithsonian Institution and heads the Amphibian Rescue Project in Panama.

"Frogs are disappearing all over the world," said Gratwicke. "About 40 percent of all of the species that we have sufficient data for, and determined their conservation status, are in danger of extinction."

The group follows the creek for a few hours in search of wild frogs. Jorge Alberto Gonzalez, their guide, is trained in capturing even the tiniest frogs in the jungle.

But it's getting difficult to find them. Scientists estimate that 120 species of frogs have vanished over the past 20 years. Most were wiped out by a disease known as Chytrid fungus.

Gratwicke takes a cotton swab and wipes this frog's feet and stomach to collect samples for analysis. He's looking for signs of the fungus that in recent years has killed nearly 80 percent of the mountain frogs in Central America and is now spreading to warmer, lower regions.

"What we are trying to do with the Panama Amphibian Rescue Project is to go out into western Panama, before the disease hits, and collect as many frogs as we can of the species that we think would go extinct, and once we get the frogs into captivity we'll try to breed them," Gratwicke explained.

Gratwicke is also a skilled photographer. He photographs every frog he captures for an amphibian project on the web.

Now, in a park near Panama City, the Smithsonian team has established temporary facilities for the captured frogs. Inside shipping containers, about 200 frogs are kept healthy in the lead up to breeding them.

"Here we have a La Loma tree frog," Gratwicke said. "It's a beautiful green tree frog that has a slight orange eye stripe and is very sensitive to Chytridia Micosis. It ranges from Costa Rica all the way to Colombia."

Gratwicke says the fungus can only be treated in captivity. This harlequin frog is native only to Central Panama.

"By the time we started our project, Chytridium had already hit Panama and it wiped out a lot of these frogs," Gratwicke recalled. "So these ones are very rare now in the wild, their population crashed. This is a very rare frog on the brink of extinction."

Keeping frogs healthy in captivity is not easy. The challenge is to produce food that has not been contaminated by the fungus. They also produce cockroaches and worms. In a separate location is a frog's favorite meal: fruit flies in almost all sizes.

"If you see in this coconut fiber this tiny little white specks crawling around, those are the springtails," noted Gratwicke. "It's the smallest food we can cultivate and that's what the baby frogs eat."

Back in Washington DC, at the National Zoo, some Panamanian golden frogs are being kept alive.

"This particular species, Panama's national animal, is highly endangered. We think they are probably extinct in the wild. So these are probably some of the last animals of the species left in the world," Gratwicke said.

Today more than 2,000 Panamanian golden frogs have been reproduced in captivity across the US.

Why are frogs so important? Gratwicke says frogs are in the middle of the food chain: they eat insects and they are food for many larger animals.

For humans, scientists believe frog skin contains chemicals that can lead to medical breakthroughs.

So far, the campaign to rescue frogs has established safety for four species in Panama. The team hopes to find a cure for the deadly fungus and one day release the healthy frogs back into the rain forest.