Amphibians landed the first time about 400 million years ago and found a rich and not so demanding habitat to live in, so they rapidly reached big body sizes and the top of the food chain, remaining enthroned on it for about 100 millions years. At the end of the Permian new land invaders - the crocodiles "prototypes" - began to compete with Amphibians both for food and place to live. This phenomenon led to the miniaturisation of Amphibians and their spreading to colder regions, where crocodiles couldn't survive for their impossibility to hibernate. Since that first radiation this animals changed their lives thousand times, powering up their skin with venoms and antimicrobial substances and adapting to nearly every habitat in the globe except the poles.
Now they are probably facing their worst period ever. Hundred of species are close to extinction or they already disappeared. The human species is probably the main cause of their drop: climate changes, habitat loss and the spreading of the chytrid fungus are devastating many populations. This last disease, that causes skin damage and suffocation to the infected animal, is even a bigger mistery: it's widespread all over the world but it has the same genetic code everywhere. This probably means that it had a very fast propagation in a few years and humans are probably the main vector. South America have been heavily attacked by the gungus in the last years: three quarters of Atelopus toads are already extinct and many species, like Telmatobius frogs and other Central and South American Amphibians, are in the same danger. Hylomantis lemur, the Lemur Leaf frog is disapperaring from most sites and all the higher altitude populations are already extinct.
The Peruvian Amazon is one of the hot spot of world biodiversity, both in cloud forests and into the flat, lush lowlands. Over there, into the Manu National Park and into the Madre de Dios area, we had the opportunity to document the effort of different researchers, like Alessandro Catenazzi team, to save Amphibian populations. They compare data form the past with actual data collected in the field and try to understand which is the impact of the Chytrid fungus. Despite some bad news new species are discovered almost each year and the Amphibian population remains in good health in some parts of this region, with the disease limited to mountain areas.

On frogs see also A forest tale: the spider and the frog

Many thanks to Alessandro Catenazzi and his team, Rudy Von May, Mo Donnelly, Nigel and Renata Pitman and all the crew of the CICRA Los Amigos biological station in the Peruvian