Discover the 3 Types of Falcons Found in Illinois Skies

Written by Tavia Fuller Armstrong
Published: December 18, 2023
Share on:


According to the Illinois Department of Natural Resources, there are at least two dozen different raptor species in the State of Illinois. These include eight different types of owls, nine different hawk species, the Mississippi kite, the osprey, the bald eagle, and the golden eagle. Three types of falcons are also commonly found in the Illinois skies. These include the American kestrel, the merlin, and the peregrine falcon. Two other falcons, the gyrfalcon and the prairie falcon, have had recorded sightings in Illinois, but they have proven extremely rare, as the state lies well outside their normal ranges.

What Is a Falcon?

Falcons are small birds of prey that share many similarities with hawks. Even novice birdwatchers can tell the difference between falcons and owls or eagles. But distinguishing falcons from hawks may take more experience.

The falcons in Illinois range from about the size of an American robin to the size of an American crow. They tend to have a more slender appearance than hawks, with longer wings proportional to their bodies. Falcons may exhibit sexual dimorphism in their markings, and females typically outsize males.

What Do Falcons Eat?

The falcons in Illinois typically prey on other birds, insects, and sometimes bats. These swift predators usually catch their prey on the wing, similar to some of the accipiter types of hawks. However, falcons can maneuver better in the air and can reach much higher speeds, particularly when they dive. Falcons also usually kill their prey differently than hawks. Hawks pierce and rip open prey with their powerful talons, while falcons have a sort of tooth built into their beak that allows them to rip open their prey at the neck.

Where Do Falcons Live in Illinois?

Some of the falcons in Illinois migrate through the state, spending their winters further south and their summers further north. Others live in Illinois year-round. Peregrine falcons, for instance, migrate through most of Illinois, but some live year-round in the northeastern corner of the state, near Chicago and Lake Michigan.

Peregrine Falcon (Falco peregrinus)

Peregrine falcons are the largest falcons in Illinois and the fastest birds on the planet.

©emranashraf/iStock / Getty Images Plus via Getty Images

The largest falcon found in Illinois, the peregrine falcon, grows to roughly the size of an American crow. Their overall length ranges from about 13 to 23 inches. Their long wings can span from around 29 to 47 inches. Using these long, powerful wings, the Peregrine falcon can reach speeds of up to 200 miles per hour in a dive, making it the fastest animal on the planet.


Male and female Peregrine Falcons look similar, with nearly identical markings. Females, however, are significantly larger than males. Both sexes have dark backs, wings, and tails, ranging from slate gray to nearly black with a blue tinge. On close inspection, the tail feathers have indistinct barring. They have a dark, nearly black head with a mustache marking on either side of their beak. Their neck and chest have plumage ranging from white to buff or tan. The undersides, likewise, have light-colored feathers with fine barring. The eyes of the peregrine falcon are rimmed in bright yellow, and the base of their beak and their legs and feet are yellow, too.


Peregrine falcons range over much of the world. They have breeding grounds on every single continent except Antarctica. Their winter grounds lie as far north as the Arctic Circle, and they breed as far south as the tip of South America. In Illinois, peregrine falcons mostly migrate through between their summer and winter ranges. However, the area around Chicago and Lake Michigan serves as a perfect habitat for a population of peregrine falcons that breed there and stick around all year.

American Kestrel (Falco sparverius)

American Kestrel

American kestrels are the smallest falcons in Illinois and range throughout the Americas.

©Katie Duncan-Burt/iStock via Getty Images

The American kestrel is the smallest of the falcons found in Illinois and the most common. This tiny raptor measures roughly the same size as an American Robin, reaching lengths between about 9 to 12 inches. They have long, slender bodies, and their long wings reach spans of 20 to 24 inches. American kestrels have less developed flight muscles than other falcons, and therefore utilize perches for hunting more than diving from the sky. Birdwatchers often spot these small falcons sitting on fences or posts near open areas where they can easily spot prey. They feed on everything from insects and other invertebrates to small mammals, birds, lizards, and frogs.


American kestrels exhibit sexual dimorphism not only in size, with females growing somewhat larger than males, but also in coloration and markings. Males have reddish-brown back and tails with dark barring. Their tails have a lighter tip preceded by a black band. They have reddish-brown breasts, fading to buff or white undersides. Their wings are dark grey with darker spots.

Females are mostly reddish-brown with dark barring, including their wings. Their undersides have light, buff plumage with darker streaks. Both sexes have dark gray on top of their heads, with white faces accented by two dark vertical bars on either side. They also have black spots known as ocelli or false eyes, on the back of their necks.


American kestrels range throughout North, South, and Central America. Commonly found in Illinois, these falcons are year-round breeding residents. They live in a variety of habitats, from forested areas to open grasslands and even in suburban areas near human populations. These birds must have access to perches for hunting. They will nest in tree cavities, the abandoned nests of other birds, and even in nest boxes.

Merlin (Falco columbarius)

Merlin perched with fresh kill blue sky background

Merlins are as small as a mourning dove and distinguished by their white eye stripes.

©Noah Li/

Merlins are roughly the size of a mourning dove, and present with a bit heavier appearance than other falcons. They may look more like tiny hawks than the other falcons seen in Illinois. Merlins range from about 9.4 to 13 inches in overall length. Their wingspan ranges from approximately 20 to 29 inches. These strong predators usually eat smaller birds, including finches, sparrows, and many others. They tend to fly low over open areas to catch their prey.


The merlin shares some of the same blue-gray coloring of the other species in the area. Its back ranges from light gray to nearly black, and the underside is light with brown streaking. The head and face of the merlin lack the strong markings of other falcons found in Illinois. Observers can look for the thin white stripe over the eye of the merlin to confirm the species. Females of this species tend to outsize males by an average of up to 40 percent. They have a lighter appearance than the males.


Merlins range mainly through the northern hemisphere, with different subspecies inhabiting different parts of the world. In Illinois, these falcons may be found migrating through the area, but they typically do not take up residence.

The photo featured at the top of this post is © Harry Collins Photography/

Share on:
About the Author

Tavia Fuller Armstrong is a writer at A-Z Animals where her primary focus is on birds, mammals, reptiles, and chemistry. Tavia has been researching and writing about animals for approximately 30 years, since she completed an internship with the U.S. Fish and Wildlife Service. Tavia holds a Bachelor’s Degree in Biology with a wildlife emphasis from the University of Central Oklahoma. A resident of Oklahoma, Tavia has worked at the federal, state, and local level to educate hundreds of young people about science, wildlife, and endangered species.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.