Individuals of these two nearly identical species are distinguishable only by chromosome number (H. chrysoscelis is diploid, H. versicolor is tetraploid) and mating call (trill rate is faster in H. chrysoscelis).

Key Characters: Large toe pads; pale spot under eye; orange or golden yellow patches in groin and inner thigh.

Similar Species: Bird-voiced treefrog, green treefrog.

Description: Medium-sized (up to 6 cm SVL) brown or greenish brown frog with a black star-shaped or irregular X-shaped blotch on back. Belly pale, throat of male dark. Dark bars on arms and legs. Pustule under joint of outer finger of hand usually not divided. Recently transformed juvenile is bright green.

Habitat: Trunks and branches of trees. Adults mate in woodland pools, roadside ditches, and other temporary bodies of water.

Natural History: May change color from dark gray to light green depending on temperature and background. Diet consists of small insects and spiders. Feeding adults and juveniles are often attracted to house lights and windows where insects accumulate. Breeds late April to August. Breeding call is a guttural trill resembling Red-bellied Woodpecker song. Eggs, laid in packets attached to vegetation at water's surface, hatch in a few days and tadpoles transform in about two months. Bold red-orange and black tadpole tail provides easy identification.

Status: Common to very common throughout Illinois, but ranges of the two species remain to be distinguished.