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great blue heron

great blue heron (Ardea herodias)

Features and Behaviors

An adult great blue heron is 42 to 52 inches long. It is the largest heron in Illinois. It has blue-gray body feathers with white coloring near its head and neck. The yellow-green legs are long and skinny. This bird has a long neck and pointed bill. Both sexes are similar in appearance.

The great blue heron is a common migrant through Illinois and a summer resident in Illinois. It winters from the southern United States to South America. The great blue heron lives in marshes, ponds, lakes, flooded fields, swamps and along the shorelines of rivers. This bird consumes mostly fishes, insects and crayfish. It has a low call of "frahnk, frawnk, frawnk." Like the other herons, its neck is held in an "S" formation during flight with its legs trailing straight out behind its body. The great blue heron migrates singly or in small flocks at any time of day. Spring migrants begin appearing in Illinois in February. These birds nest from March through May, usually with other herons in tree colonies called rookeries. The nest is a platform of large sticks arranged in a tall tree. Three to six blue-green eggs are laid. Birds disperse to the north after nesting.

Illinois Range


​Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Pelecaniformes
Family: Ardeidae

Illinois Status: common, native