Michigan's Department of Natural Resources is looking for volunteers for its annual frog and toad survey.
The DNR says the survey helps biologists monitor how Michigan's amphibians are doing.
Coordinator Lori Sargent says spring is the best time to estimate frog and toad populations in Michigan.
"This is when they call, when it starts to get warm and the water temperature gets warmer because they're calling for mates and establishing their territory," Sargent said.
Though frog and toad populations have been falling nationwide, numbers in Michigan are more stable.
Sargent says amphibians are critical members of Michigan's ecosystem.
"They're an important part of the ecosystem, they're food for a lot of different animals and they eat a lot of mosquitos and other insects," Sargent said.
Volunteers listen for toad and frog calls, identify the species, and estimate their abundance.