CHICAGO— The Center for Biological Diversity today sued the U.S. Fish and Wildlife Service over its decision to not protect the Illinois chorus frog under the Endangered Species Act.

The frogs’ spring choruses once filled the sand prairies of the Midwest, but virtually all their native habitat has been lost to agriculture and development.

“Science shows that these chubby, burrowing frogs are losing habitat fast and that they warrant protection, so federal officials made a big mistake here,” said Lindsay Reeves, a senior attorney at the Center. “The Fish and Wildlife Service needs to go back and do its homework about the threats these frogs face before their chorus fades forever.”

Illinois chorus frogs survive only in scattered and isolated populations in Arkansas, Missouri and Illinois. They need sandy soil for burrowing and temporary wetlands for their tadpoles to grow in. In denying the frog Endangered Species Act protection, the Service assumed that all croplands could be habitat for the frog even though practices like laser-leveling and wetlands filling eliminate these conditions.

In fact, the Service ignored wetlands loss across the frogs’ range altogether when deciding not to protect them.

The Center petitioned the Service to protect Illinois chorus frogs under the Endangered Species Act in 2012. In 2015 the agency found that federal protection may be warranted, but it reversed course in its final decision in 2023. This leaves the frogs without federal safeguards necessary for their survival.

The Service also declined to protect any of the distinct populations of the frog, including the Arkansas population, even though scientists warn that the frog is at imminent risk of extinction there.