LANSING, MI (AP)-- State officials need volunteers to help with Michigan's annual frog and toad survey.
Populations of frogs, toads and other amphibians have been falling since the 1980s.
Scientists say the likely causes include habitat loss, pollution, disease and human collection.
The Department of Natural Resources says the survey helps biologists monitor how Michigan's amphibians are doing.
Coordinator Lori Sargent says data gathered over the past 20 years suggests that Fowler's toads and mink frogs are declining in Michigan. They have a limited range, while other amphibian species are found statewide.
Observers conduct the surveys by visiting wetland sites three times during spring breeding season. They listen for toad and frog calls, identify the species and estimate their abundance.
To learn about becoming a volunteer, visit Michigan.gov/wildlife or contact Sargent at 517-284-6216.