Illinois is a significant location for hawks, serving as a year-round home for some species and a major migratory thoroughfare for others. The state’s position directly underneath the Mississippi Flyway funnels millions of birds, including various raptors, through its airspace twice a year. This geographical placement, combined with a diverse mix of habitats from dense forests to wide-open agricultural fields, ensures that hawks are a regular and abundant sight.
Key Hawk Species Found in Illinois
The most frequently observed raptor is the Red-tailed Hawk, a large and adaptable bird often seen perched on utility poles or soaring high above open fields. This heavy-bodied Buteo is recognizable in adulthood by its characteristic brick-red tail, though juveniles possess a banded brown tail. Red-tailed Hawks are generalist predators, feeding primarily on small mammals like mice and voles found in the expansive agricultural landscapes of Illinois.
Another common resident is the Cooper’s Hawk, a sleek and agile raptor that belongs to the Accipiter group, known for their short, rounded wings and long tails. Cooper’s Hawks have successfully adapted to suburban and urban environments, where they frequently hunt smaller birds, including those at backyard feeders. They are slightly larger than a crow, with adults displaying a bluish-gray back and reddish barring on the chest.
Closely related is the Sharp-shinned Hawk, the smallest of the North American hawks, which shares the same swift, forest-dwelling hunting style. While often confused with the Cooper’s Hawk, the Sharp-shinned is notably smaller and has a distinct square-tipped tail, compared to the Cooper’s rounded tail.
Habitats and Seasonal Migration Patterns
Hawk populations in Illinois are distributed across several distinct environments, with certain species showing preferences for specific habitats. Red-shouldered Hawks, for instance, are year-round inhabitants of moist woodlands and bottomland forests, particularly favoring areas near rivers and swamps in the southern and western parts of the state. In contrast, the ubiquitous Red-tailed Hawk thrives in the mosaic of open country, forest edges, and prairie remnants that characterize much of central Illinois.
The seasonal movement of raptors is heavily influenced by the state’s location along the Mississippi Flyway, one of the continent’s major bird migration corridors. During the fall, hawks traveling south rely on thermal currents to conserve energy during their long flights. Species like the Broad-winged Hawk are most visible during this period, forming large, swirling flocks known as “kettles” as they pass through the state on their way to Central and South America.
These migratory paths are often concentrated along geographical features that hawks tend to avoid flying over, such as large bodies of water. The shoreline of Lake Michigan acts as a natural funnel, pushing thousands of migrating raptors, including Sharp-shinned and Broad-winged Hawks, into narrow corridors in places like Illinois Beach State Park and Fort Sheridan. Illinois also hosts winter-only visitors, such as the Rough-legged Hawk, which migrates south from its Arctic breeding grounds to hunt over the open fields during the colder months.
Practical Tips for Identifying Illinois Hawks
Identifying hawks in the field relies heavily on observing their body shape and flight style, which can broadly categorize them into two main groups. The Buteo hawks, which include the Red-tailed and Broad-winged, are characterized by their broad wings and short, wide tails, making them excellent at soaring in wide circles. The Red-tailed Hawk often shows a pale underside with a dark band of streaking across the belly, a useful identifying feature.
The Accipiter group, represented by the Cooper’s and Sharp-shinned Hawks, feature short, rounded wings and long tails, allowing them to maneuver quickly through dense forest cover. These raptors employ a distinctive flight pattern of a few rapid wing beats followed by a brief, level glide, often flying low to the ground. Differentiating between the two requires noticing the size difference and the shape of the tail tip: rounded on the Cooper’s Hawk and square on the smaller Sharp-shinned Hawk.
To avoid misidentification, it is useful to distinguish hawks from other common Illinois raptors. The Northern Harrier, for example, is easily recognized by its slim body, a distinct white patch above the tail, and a habit of flying low over fields with its wings held in a shallow “V” shape. Turkey Vultures, which are also often seen soaring, can be separated by their black plumage, larger size, and the way they hold their wings in a pronounced dihedral, or “V” shape, while wobbling slightly as they ride the thermals.