The merlin is also known as the pigeon hawk. This bird averages 10 to 14 inches in length (tail tip to bill tip in preserved specimen). The male has blue-gray feathers on the back with wide, black bands on a gray-feathered tail. The female and young have dark brown feathers on the back with a banded tail. All of these birds have light belly feathers and chest feathers with dark streaks.
The merlin is an occasional migrant and rare winter resident in Illinois. It may be seen in woodland edges and open areas as it travels through the state. Sometimes this raptor is present at mud ﬂats, where it attempts to catch shorebirds. Spring migrants begin arriving in Illinois in April and May on their way north. The merlin breeds in the northern United States and Canada, where it can be found in open, conifer woodlands. The nest is composed of sticks placed in a tree cavity, on a ledge or on an old, bird nest. Four or five, white eggs, heavily marked with dark spots, are deposited by the female. She does most of the incubation over the 30-day, incubation period. Fall migrants begin arriving in Illinois in August. The merlin winters as far south as Peru and Venezuela. It eats birds, rodents and insects.