Early Warning Sign?
Amphibians around the world are vanishing—and may signal danger to our global ecosystem's health. Why?
Amphibians feel the effects of environmental changes long before we do, partly because of their sensitive skin and watery way of life. In fact, one-third of all known amphibian species are threatened with extinction. The greatest threats are pollution and climate change, but disease, habitat destruction and fragmentation, and invasive species are also affecting amphibians.
The IUCN's Amphibian Specialist Group is working to study, save, restore, and manage amphibians and their habitats around the world.
Amphibians breathe partly through their skin—taking in vital oxygen. But the permeability that makes their skin special also makes amphibians sensitive to pollution in the soil, air, and water.
Zoom in on the White's tree frog below to see how wet the skin is. You can even see the pores.
Leading a Double Life
Amphibian means "double life" in Greek. Many amphibians start life in the water, and, through a dramatic transformation (metamorphosis), develop into adults that live mostly on land.
As the tadpole starts changing into a frog, hind legs grow. Soon front legs also appear. Later, the tail shrinks and the tadpole develops lungs—then it can come out on land.
Squares link to animal fun facts.