The common gallinule is about 14 inches in length (bill tip to tail tip in preserved specimen). The red bill that extends to a red plate between the eyes, yellow bill tip and white stripe along the sides are characteristic traits of this bird. The bill in immature common gallinules is not brightly colored.
This bird is an uncommon migrant and local summer resident in northern Illinois. It is occasionally seen migrating in central and southern Illinois and may be a summer resident in these locations. Spring migrants begin arriving in late April. Fall migration starts in early September. This species winters in the southwestern United States and Central America. The common gallinule frequents marshy areas and lakes seeking the plants, seeds, aquatic macroinvertebrates and amphibians that it eats.