Hear Me Croak!

Most frogs spend their lives in wetlands, such as marshes, swamps, and ponds. Unfortunately, people destroy these regions to construct houses, factories, and farms. And as wetlands vanish, so do frogs. Pollution can also harm frogs and destroy their populations.

That’s why scientists wanted to know: Are these changes to wetlands putting frogs at risk?

The volunteers enter their observations into a website that scientists can access. The data reveals where different frog species are living.

Over time, it shows whether frog populations in a particular area are in trouble. For instance, volunteers listening at a stream might have once heard frog calls in the past but then stopped hearing them. That could suggest that a species might have disappeared from the stream.

Frogs make noises to attract mates. Every species has a different call. Frogs make noise by moving air between their lungs and stretchy throat pouches called vocal sacs. These sacs can inflate like balloons.

To record these calls, volunteers first receive training from local FrogWatch staff to learn what to listen for. Then they trek out to the wetlands at least three times each season. They spend three minutes writing down which species of frogs they hear and how noisy they are.

Monitoring frog calls can help scientists figure out whether conservation efforts are working. Rachel Gauza is a biologist at the Department of Energy and Environment in Washington, D.C. She leads a project to protect wetlands. FrogWatch volunteers listen for frogs at these sites. If they don’t hear as many croaks, that’s a signal that a wetland may need more protection.

Citizen scientists like Ann Earley and the other FrogWatch volunteers can help scientists collect much more data than they ever could alone. “It’s a team effort!” says Gauza.