Illinois Chorus Frog

The Illinois chorus frog is small (up to 4.7 cm ) tan to gray, with dark brown or black lines on its back.  It has a white belly with granular skin.  The throat (vocal pouch) of the male is dark during breeding season.  They eat small insects and burrowing insect larvae.  

Illinois chorus frogs are fossorial, which means they are adapted to digging and burrowing. The Illinois chorus frog uses its front legs to burrow in the sandy soil. They emerge from their burrows only to breed during late winter and occasionally to feed during summer rains. Courtship starts in February, and may continue into early April. Frogs are stimulated to migrate between their burrowing areas and the breeding pools when heavy rains occur and temperatures exceed 48 degrees Fahrenheit. The breeding call of the males is a distinct high-pitched series of rapid, bird-like whistles. Most calls begin after dark and continue into the night.  Females lay 200 to 400 eggs, which are fertilized externally by the male. Tadpoles develop into sub-adult frogs by May or June. 

Habitats include sandy grasslands, wetlands, and agricultural areas. In late winter, they prefer temporary pools in herbaceous wetlands, bottomlands, and floodplains. Wetland draining and habitat changes have forced them to use alternative habitats such as flooded roadside ditches, cultivated fields, flooded pastures, cattle ponds, sloughs, and small remnant wetlands.