The world is home to thousands of species of frogs living on every continent except Antarctica. Most frogs spend their lives in wetlands, such as marshes, swamps, and ponds. These watery spots are teeming with living things, from algae and insects to fish. Forty-three percent of threatened and endangered plants and animals in the U.S. live in wetlands.
Frogs depend on these soggy landscapes to survive. They lay their eggs in water. When frogs are young, they live underwater as tadpoles. Adult frogs have special skin that allows them to absorb nutrients and oxygen directly from the water.
Unfortunately, people are draining wetlands, or drying them out, to build cities and farms. And as wetlands vanish, so do the frogs that live there. Rain and snowmelt can also carry pollution from cities and farms to wetlands. That pollution can make frogs sick. All these habitat changes can also cause frogs stress, making them vulnerable to disease.
Frogs are extremely sensitive to their surroundings. Studying them can reveal the health of the environment, says Rachel Gauza. She’s a biologist at the Department of Energy and Environment in Washington, D.C. “Amphibians are like superheroes who signal when something is going wrong.”