Hawks belong to a broad group of diurnal birds of prey, or raptors, characterized by powerful talons, sharp beaks, and superb vision. The term “hawk” is commonly applied to a variety of species within the Accipitridae family, which includes the broad-winged soaring hawks (Buteos) and the slender, agile “true hawks” (Accipiters). Determining the absolute largest species depends on whether size is measured by total body length, wingspan, or overall body mass. While many raptors are larger, the Ferruginous Hawk is consistently ranked as one of the heaviest and most imposing species within the commonly accepted definition of a hawk.
Identifying the World’s Largest Hawk Species
The title of the largest hawk species by weight is a close contest between the North American Ferruginous Hawk (Buteo regalis) and the Asian Upland Buzzard (Buteo hemilasius). Female Ferruginous Hawks are the heaviest, reaching a maximum recorded mass of up to 2,074 grams, or approximately 4.5 pounds. This robust weight is supported by a large frame that can measure up to 69 centimeters (27 inches) in total body length.
Wingspan typically ranges from 133 to 152 centimeters (52 to 60 inches) for this species. The Upland Buzzard, while having a slightly longer wingspan at up to 161 centimeters (63 inches), often has a comparable or slightly lower average mass, placing the Ferruginous Hawk as the bulkiest species. This sheer mass makes the Ferruginous Hawk an exceptionally powerful raptor. Its scientific name, Buteo regalis, directly translates to “royal buzzard,” a nod to its commanding size among its relatives.
Where the Largest Hawk Lives
The Ferruginous Hawk is a raptor exclusive to North America, inhabiting the vast, open landscapes of the continent’s western interior. Its range extends from the Canadian prairies southward through the western United States and into northern Mexico. This hawk is a species of the open country, preferring habitats such as arid plains, high deserts, and semiarid grasslands.
The hawk’s preference for wide-open spaces is tied to its hunting style and its need for clear sightlines to spot prey. It avoids heavily forested areas and mountainous terrain, instead favoring environments with abundant ground-dwelling mammals. Nesting sites typically involve scattered trees, low cliffs, or even the ground itself where elevated perches are scarce.
Size Differences Among Major Hawk Groups
The concept of a “hawk” is taxonomically broad, and the large size of the Ferruginous Hawk is a feature of its group, the Buteos. These broad-winged hawks, often called buzzards outside of North America, are generally stocky birds built for soaring and utilizing thermal air currents. The common Red-tailed Hawk (Buteo jamaicensis), for example, is a large Buteo, but its maximum weight and wingspan are consistently eclipsed by the Ferruginous Hawk’s largest individuals.
The other main group of hawks, the Accipiters, or “true hawks,” are designed differently with shorter, rounded wings and long tails suited for maneuverability in woodlands. The largest Accipiter species is the Northern Goshawk (Accipiter gentilis), but it is significantly smaller than the largest Buteos. The Goshawk’s maximum mass is typically around 1,360 grams (3.0 pounds), and its wingspan rarely exceeds 115 centimeters (45 inches). This difference highlights that the largest hawks are specialized for open-air hunting and bulk, contrasting with the Accipiters’ adaptation for agility in dense cover.
Hunting Strategies and Prey
The Ferruginous Hawk’s large size dictates a diet primarily consisting of medium-sized ground mammals, which it is physically equipped to overpower. Its main prey items include ground squirrels, prairie dogs, pocket gophers, and jackrabbits. The hawk’s heavy-duty feet and large talons are highly effective at capturing and holding these substantial, burrowing animals.
The species employs several distinct hunting methods that capitalize on its size and power. It frequently hunts by soaring high above its grassland territory, using its sharp eyesight to locate prey before executing a swift, powerful dive. It is also known to hunt from elevated perches, such as power poles or rock outcrops, or by hovering above detected prey. This hawk occasionally hunts on foot, walking over the ground to ambush small mammals as they emerge from their burrows.