Amphibians were the first group of vertebrates to successfully conquer land almost 400 million years ago. They are thought to have evolved from animals similar to the air-breathing lungfish, one species of which can be seen in our Okapi exhibit.
There are over 6,000 species of amphibian. They belong to one of three groups - frogs and toads, salamanders and caecilians. New species of amphibian are being discovered by scientists all the time. In 1998 over 200 undescribed species were recorded in Sri Lanka alone. However, as new species are discovered, others are going extinct.
In 1988 scientists started reporting a very worrying trend where amphibian species had started to disappear from apparently pristine natural habitats. Over 50 species are now known to have disappeared forever and we still don't know what is causing the decline. Possible culprits include climate change, UV radiation, pollution and disease.
At Chester Zoo our amphibians can be found in the Aquarium, the Tropical Realm and the Spirit of the Jaguar exhibit. They include the world's most poisonous land vertebrate the Golden Poison Dart Frog - the toxins produced from the skin of a single specimen of this species would be enough to kill 100 adult humans. Two of our toad species the Mallorcan Midwife Toad and the Puerto Rican Crested Toad are part of species recovery programmes that have seen animals bred and then reintroduced to the wild in efforts to save the species from extinction.