Big Marsh Park attracts more than 150 bird species throughout the year and its extensive urban wetland makes it an especially good place to spot water-loving birds such as great blue herons, egrets, and mallards. Big Marsh is also a fantastic site for spotting highly secretive marsh birds such as the Virginia rail, least bittern, and common gallinule. Secretive marsh birds are more often heard than seen.

Since 2015, Audubon Great Lakes has led surveys of secretive marsh birds at wetlands in the Calumet region in Illinois. The Illinois Calumet Marsh Bird Survey welcomes volunteers, both beginners and advanced birders to participate. The bird survey focuses on the following focal species: American Bittern, Least Bittern, Black Rail, Sora, Virginia Rail, King Rail, Common Gallinule, and Pied-billed Grebe. Data are also collected on a set of secondary species. 

Three Secretive Marsh Birds You Might Hear or See at Big Marsh Park

Virginia Rail (Rallus limicola)

The Virginia rail is a small waterbird, of the family Rallidae. According to ebird.org, the Virginia rail is “found in freshwater marshes but also found in brackish and saltwater; prefers extensive cattails or reeds but also found in shrubbier marshes. Shy and not often seen, but sometimes wanders along the edge of reeds. According to All About Birds, the Virginia rail builds numerous "dummy nests" in addition to the one where eggs are actually laid. It is most easily detected by voice. Male "song" is a series of doubled "kiddik, kiddik" notes; most common call is a descending, accelerating series of grunts.” Listen to the song of the Virginia rail and watch a video here.

Least Bittern (Lxobrychus exilis)

According to the Illinois Department of Natural Resources, the least bittern “averages 11 to 14 inches in length and both male and female have a similar appearance. There is a light, tan patch on each wing, and a dark cap can be seen on the head. The back has dark feathers with two, white stripes while the lower side has tan feathers. The pointed bill is thick.”  According to All About Birds, when alarmed, the Least Bittern freezes in place with its bill pointing up, turns both eyes toward the source of alarm, and sometimes sways to resemble windblown marsh vegetation. The least bittern is threatened in Illinois. Listen for the least bittern’s soft cooing song, given during the day and at night. Watch a video of the least bittern here.

Common Gallinule (Gallinula galeata)

The common gallinule is about 14 inches in length. Characteristics of the common gallinule include a red bill that extends to a red plate between the eyes, a yellow bill tip and a white stripe along the sides, according to the Illinois Department of Natural Resources. The bill in immature common gallinules is not brightly colored. The common gallinule swims like a duck and walks atop floating vegetation like a rail with its long and slender toes. According to All About Birds, Listen for a strange clucking and whinnying coming from thick marsh vegetation and start scanning the edges. It often peeks in and out of vegetation, either walking atop vegetation or swimming along the edge.  Listen to the song the common gallinule and watch a video of the bird here.