The term “hawk” is commonly used by the public to describe almost any medium-sized bird of prey seen soaring overhead or perched on a pole. This broad usage often includes birds that ornithologists classify as eagles, falcons, or harriers. In the scientific community, the word refers to a more specific set of birds. The true classification of these raptors helps distinguish their unique evolutionary adaptations and hunting strategies.
The Definition of a Hawk and the Global Count
Hawks belong to the family Accipitridae, a group within the order Accipitriformes that also includes eagles, kites, and Old World vultures. In North America, the term typically covers species in the genera Buteo, Accipiter, and Parabuteo. In many other parts of the world, however, Buteo species are known as “buzzards.”
The most restrictive classification defines “true hawks” as only those species within the genus Accipiter. Considering the most common usage—which includes the Accipiter and Buteo groups along with a few related genera—there are approximately 270 different species of hawks worldwide. These species are found on every continent except Antarctica, adapting to nearly every terrestrial environment.
Structural Groups and Hunting Styles
Ornithologists categorize hawks primarily into two structural groups based on their morphology. The first group, known as the buteonine hawks or Buteos, are characterized by their broad, rounded wings. These features make them exceptional at soaring. They typically have shorter, broad, and square tails, which provide stability during high-altitude searching.
Buteos employ a sit-and-wait hunting style, often perching on high vantage points like telephone poles or trees to scan for ground-dwelling prey. Once prey is spotted, they descend rapidly or pounce to secure small mammals, reptiles, or large insects. Their robust build and broad wings are ideal for sustained, energy-efficient flight over grasslands, deserts, and agricultural fields.
The second major group is the accipitrine hawks, or Accipiters, which have a distinctly different structure optimized for agility in cluttered habitats. Accipiters possess shorter, rounded wings and very long tails relative to their body size. This morphology allows them to maneuver quickly and precisely through dense forests and woodlands. The long tail acts like a rudder, enabling swift changes in direction while chasing agile prey.
Their hunting style involves rapid pursuit, often darting from a concealed perch to catch small birds and mammals in flight or near cover. Their flight pattern is characterized by a distinctive rhythm of rapid wingbeats followed by a short glide, often described as “flap, flap, flap, glide”. This contrast in wing and tail design represents a clear evolutionary divergence, reflecting the specific ecological niche and prey each group targets.
Geographic Distribution and Field Identification
Buteonine hawks, such as the Red-tailed Hawk, are most commonly sighted in open areas across North America, including along highways and over large fields. When soaring, their broad wings are held out almost flat, and their flight appears relaxed, making long, gentle arcs as they circle on thermals. The Red-tailed Hawk, in particular, is often the first hawk a birdwatcher sees due to its abundance and tendency to perch prominently.
Accipitrine hawks, including the Cooper’s Hawk and Sharp-shinned Hawk, are more often found near or within wooded habitats. Identifying these birds in flight involves recognizing their unique silhouette—a relatively small head, short wings, and a long tail that gives them a “flying cross” appearance. Their flight is more energetic and purposeful, marked by the quick, shallow wingbeats that power them through the forest canopy.
Assessing the overall shape, or silhouette, is key for field identification. A birder who spots a hawk soaring with broad wings over a prairie can confidently narrow the identification to a Buteo. Conversely, a bird exhibiting a rapid, flap-and-glide flight pattern while darting between trees is almost certainly an Accipiter. Understanding the link between morphology and habitat provides a practical framework for identifying these diverse raptors.