A great horned owl can crush the skull of a full-grown skunk without flinching from the smell, while a saw-whet owl small enough to cup in two hands hunts the same Illinois woodlots just a few miles away. That size range is part of what makes the types of owls in Illinois so rewarding to track down, whether from a gravel road near Springfield or a lakefront trail in Cook County. Nine species turn up across the state with real regularity, from Arctic wanderers that only visit in winter to year-round residents that nest in barns, tree cavities, and city parks.
Each species favors its own habitat, hunting schedule, and call, and knowing those differences turns an ordinary walk at dusk into a real chance at a sighting. This guide walks through all nine, covering size, range, and the best places and seasons to look for each one.
| Owl | Approximate Size | Illinois Status | Best Season to Spot |
|---|---|---|---|
| Snowy Owl | 20-27 in. | Rare winter visitor | November-March |
| Long-eared Owl | 13-16 in. | Uncommon migrant/winter resident | October-April |
| Short-eared Owl | 13-17 in. | State endangered | Fall-winter, dawn/dusk |
| Barred Owl | 17-20 in. | Year-round resident | Year-round |
| Northern Saw-whet Owl | 7-9 in. | Winter resident | Late fall-winter |
| Eastern Screech Owl | 7-10 in. | Year-round resident | Year-round |
| Barn Owl | 16-24 in. | State endangered | Year-round, rare |
| Great Horned Owl | 18-25 in. | Year-round resident | Year-round |
| Northern Hawk-owl | 14-17 in. | Accidental/vagrant | Rare winter records |
For a broader look at how these species compare to owls found elsewhere in North America, the different types of owls guide breaks down families and traits beyond what’s covered here.
1. Snowy Owl
The snowy owl (Bubo scandiacus) is the species most Illinois birdwatchers hope to see, and for good reason. According to the Illinois Department of Natural Resources,
the snowy owl averages 20 to 27 inches in length, has white feathers with dark flecks, and a large, round head with huge yellow eyes that face forward. It is also, by weight, one of the few birds that can get even non-birders to come out for a look, showing up irregularly in winter to hunt in windswept fields or dunes, according to Cornell Lab’s All About Birds.
In Illinois, the species is an Arctic owl that occasionally winters in the state, mainly in the northern one-half. When it does arrive, it may be seen in prairies, fields, marshes, lake edges, airports, golf courses and cities where it is active during the day, a habit that sets it apart from most nocturnal owls. IDNR notes that fall migrants usually appear in November, and spring migrants leave Illinois in March. Sightings tend to cluster along Lake Michigan and in open farm country farther north, and birders chasing the same irruption often check reports from owls in Minnesota, where the species shows up with similar unpredictability most winters.
Pro Tip: Snowy owls hunt and rest in the open during daylight, so scan fence posts, grain elevators, and airport perimeters rather than tree canopies when searching for this species.
2. Long-eared Owl
The long-eared owl (Asio otus) is a slim, secretive bird easy to overlook even where it roosts in groups. Per the Illinois Department of Natural Resources, it averages 13 to 16 inches in length, about the same size as an American crow, with long ear tufts set fairly close together and brown feathers streaked lighter on the belly.
This owl is an uncommon migrant and winter resident in Illinois, and an occasional summer resident in the northern two-thirds of the state. It favors conifer groves, deciduous woodlands, orchards and thickets, roosting in conifer groves during the day while perching close to a large tree trunk, often in groups. When alarmed, it stretches its body and ear tufts so that they are camouflaged better by the tree trunk. Fall arrivals typically begin in October, according to IDNR data. Birders in neighboring states track similar winter roosts, and the pattern repeats closely with sightings noted in the owls in Indiana guide, since both states share the same migratory corridor along Lake Michigan’s southern basin.
3. Short-eared Owl
The short-eared owl (Asio flammeus) is one of the few owls active enough at dawn and dusk to be seen hunting in open daylight over grassland. The Illinois Department of Natural Resources lists it as a state-endangered species, and destruction of wetland and grassland habitats is the main reason for its endangered status, meaning preservation of large blocks of prairie and marsh habitat is necessary for the species to survive in the state. Wikipedia’s list of the state’s protected wildlife similarly names the short-eared owl (Asio flammeus) among Illinois’s endangered species.
Physically, it averages 13 to 17 inches in length with a light brown, dark-brown-streaked pattern, a large head with a dark, circlelike face, large forward-facing yellow eyes, short “ear” tufts, and a tan wing patch visible in flight. IDNR describes it as an uncommon migrant and winter resident and a rare summer resident throughout Illinois that was once probably the most abundant owl species in the state, living in prairies and marshes and roosting in grassy fields or pines. Readers interested in the full scope of the state’s at-risk species can find more context in the endangered animals in Illinois guide.
4. Barred Owl
The barred owl (Strix varia) is one of the easiest Illinois owls to identify by ear, thanks to its rhythmic, eight-note call that many birders describe as sounding like a question. It is a stocky, round-headed bird without ear tufts, with brown-and-white barred plumage across the chest and streaking down the belly.
Barred owls favor mature, dense woodlands with a mix of hardwoods and conifers, especially forests near rivers, swamps, or floodplains where they hunt small mammals, amphibians, and crayfish. In Illinois, the species is most reliably found in the forested bottomlands of the southern third of the state, though it also nests in wooded river corridors farther north. Because barred owls depend so heavily on water-adjacent forest, the same bottomland habitat also supports several of the state’s wading birds; readers exploring that overlap can check the herons in Illinois guide for species that share these wetland forests.
5. Northern Saw-whet Owl
The northern saw-whet owl (Aegolius acadicus) is the smallest owl regularly found in Illinois, and its size alone makes it a favorite among birders lucky enough to spot one. The Illinois Department of Natural Resources describes it as a winter resident of Illinois woodlands measuring 7 to 9 inches long with a wingspan of 18 to 24 inches, and this small owl has no ear tufts. IDNR also notes red streaks on the belly feathers, white streaks on the forehead, and a black bill, and that it hunts at night, feeding on small mammals.
Its diminutive size backs up what other researchers have found statewide: northern saw-whet owls are the smallest owls in the state, only six to nine inches long, with a wingspan of 16 to 20 inches, according to A-Z Animals. Because saw-whets migrate along the same routes tracked by banding stations across the Midwest and New England, their movements are often compared to records from the owls in Vermont guide, where saw-whet banding data helps confirm regional migration timing each fall.
Key Insight: Saw-whet owls roost quietly in dense conifers during the day and rely almost entirely on camouflage rather than flight to avoid detection, which is why most sightings happen by accident rather than active searching.
6. Eastern Screech Owl
The eastern screech owl (Megascops asio) is proof that owls do not need to be large to be memorable. This compact, cavity-nesting owl comes in two main color morphs, a rusty red-brown and a mottled gray, and both occur across Illinois regardless of region or season.
Rather than screeching, the species is better known for a descending, tremulous trill and a shorter whinny-like call, both of which carry well through suburban yards and wooded parks at dusk. Eastern screech owls adapt readily to human development, often nesting in backyard boxes, old woodpecker holes, and mature shade trees in towns and cities across the state. Their range and habitat flexibility overlap closely with populations described in the owls in Virginia guide, since screech owls occupy a similar mix of woodland and residential habitat across much of the eastern United States.
7. Barn Owl
The barn owl (Tyto alba) is one of Illinois’s rarest and most distinctive owls, instantly recognizable by its pale, heart-shaped face. According to the Illinois Department of Natural Resources, the barn owl nests and roosts in old barns and other abandoned buildings near prairies, farms, marshes and open areas, has a white, heart-shaped face and long legs, and the middle talon on each foot is serrated.
The species’ decline in Illinois has been steep enough that the state’s Endangered Species Protection Board published a dedicated recovery brochure. That document notes barn owls have a striking appearance with whitish plumage and distinctive heart-shaped facial ruffs, and are found in a variety of open habitats in tropical and temperate zones around the world.
It adds that barns, grain bins, silos, belfries, nest boxes, and a variety of other human structures may all be used for nesting, in addition to natural nest sites such as tree cavities and dens on cliffs and bluffs, and that barn owls sometimes nest two or more times in a year when prey are plentiful, with late spring-early summer marking the peak of nesting activity.
Because the species remains far more common in warmer climates, Illinois sightings are often compared with population data from the owls in Louisiana guide, where barn owls nest in far greater numbers year-round.
Important Note: Barn owls are a state-endangered species in Illinois, and short-eared owls share that designation. Disturbing active nests or roosts of either species can violate state wildlife protections, so observers should keep a respectful distance and avoid approaching known nest sites.
8. Great Horned Owl
The great horned owl (Bubo virginianus) is the powerhouse of Illinois’s owl population, both in size and in the range of prey it takes down. IDNR describes an adult as 18 to 25 inches long, with brown body feathers, a rust-colored belly marked with black, a white throat and chest, feather tufts or “horns” on each side of the head, a flattened face with yellow eyes, large hooked talons, and feathered feet.
This owl lives in woodlands and thickets and is a nocturnal bird of prey that eats birds, cats, Virginia opossums, skunks, squirrels, woodchucks and nearly anything else it can kill, often seen at dusk or dawn sitting at the top of a tall tree or utility pole.
It is also remarkably early to breed: this owl is one of the earliest nesting birds and will nest as early as January, often placing its nest in an old crow, hawk or squirrel nest, in a tree cavity or in a building, where two to three round white eggs are laid. Its size and predatory range put it in the same conversation as the state’s largest daytime raptors, a comparison covered in the eagles in Illinois guide.
9. Northern Hawk-owl
The northern hawk-owl (Surnia ulula) is the rarest entry on this list and the one most Illinois birders will never see without traveling. This boreal forest species breeds across Canada and Alaska and behaves more like a hawk than a typical owl, hunting by day from an exposed perch and flying with quick, direct wingbeats rather than silent gliding.
Its long tail, streaked underparts, and habit of sitting atop the tallest available spruce or snag make it distinctive when it does appear. Illinois records are essentially accidental, tied to occasional southward pushes during years when prey crashes farther north in the boreal forest. When these movements happen, sightings tend to concentrate first in the upper Midwest, which is why serious owl-watchers keep an eye on reports from the owls in Wisconsin guide before checking closer to home.
Illinois’s nine owl species cover an unusual range of size, behavior, and rarity, from a bird small enough to perch on two fingers to one strong enough to kill prey many times its own weight. Learning each species’ preferred habitat and season turns a random evening walk into a genuine chance at a sighting, whether that means checking a barn roofline at dusk, listening for a barred owl’s call along a wooded river, or scanning open farm fields after a cold front pushes a snowy owl south.
For readers building out a broader picture of the state’s wildlife, the salamanders in Illinois guide covers another group of species that share the same forest and wetland habitats these owls depend on.