Hawks and eagles belong to the family Accipitridae, along with ospreys, kites, harriers, and Old World vultures. These medium-sized to very large day-flying predatory birds are found throughout the world. They are all distinguished by their strong beaks and feet, used for catching and tearing apart their prey, but are quite diverse. This is one of the families of birds in which the females are larger than the males; in eagles they may be as much as 30% larger. Hawks are distinguished from falcons by their generally broader wings and lack of “tooth” on the upper beak. Saskatchewan has 13 of the 24 species which regularly occur in North America; all are migratory, except for the northern goshawk. The accipitrids found in Saskatchewan are of six distinctive types: ospreys, eagles, buteos, accipiters, harriers, and kites. The osprey (Pandion haliaetus), sometimes called “fish hawk,” nests in large structures on dead trees or telephone poles, which the pair uses annually. In the boreal forest and northern parklands this large dark-backed, white-bellied bird with a black eye mask breeds near the water where it feeds; it is seen in migration in the grasslands.
There are two types of eagles in the province. The bald eagle (Haliaeetus leucocephalus) is one of the fish-feeding eagles found around water; the adults, with their distinctive white heads and tails, nest throughout the boreal forest, on the edges of lakes and rivers. The dark-brown golden eagle (Aquila chrysaetos) feeds on small mammals; it usually nests on cliffs, and will be seen in the summer in the southern badlands, along some of the large river valleys, and near Lake Athabasca. Both eagles are seen in migration farther south.
Five broad-winged buteos occur in the province; these common and widely distributed hawks are typically predators of small mammals. As they can occur in a number of colours of plumages, they are very confusing to identify. The red-tailed hawk (Buteo jamaicensis), a widespread hawk which is a common nester in the aspen parklands, has a dark phase, a light phase and the typical red-tailed, white-chested form. The smallest buteo, about the size of a crow, is the broad-winged hawk (B. playpterus), a fairly common nester in deciduous woodlands near water, and transient elsewhere. The brown-chested Swainson’s hawk (B. swainsoni), which preys on ground squirrels, is one of the common grasslands hawks. The other is the ferruginous hawk (B. regalis), a handsome bird with white belly and chest, and reddish legs and wings; this species is apparently recovering from a population crash and is seen more often than several decades ago. The rough-legged hawk (B. lagopus) is a common transient to and from its northern breeding grounds; being one of the few buteos which hover while hunting, it can be identified by that habit and by the dark wrist patches in the underside of the wing.
Three accipiters, or bird hawks, occur in Saskatchewan. These are highly maneuverable fliers, with pointed wings and long tails. They are also an example of the size scaling which can be seen in hawks occupying the same habitat. The smallest is the sharp-shinned hawk (Accipiter striatus), found through much of the province in the wooded areas in which it nests. The medium-sized Cooper’s hawk (A. cooperi), which also has a dark cap and thin chesnut bars on the underside, is characteristic of the wooded areas of the grasslands and aspen parklands. The larger northern goshawk (A. gentilis) breeds in the coniferous forests of the north and in the Cypress Hills, but winters farther south; it shares the dark cap of the other accipiters, but has gray barring and a gray back.
The northern harrier (Circus cyaneus) is a common sight over the open areas of the province, particularly in the south. This ground-nesting hawk, with its long tail and broad wings, flies low over the grasses and crops in search of small rodents and other prey; the gray male and brown female are often mistaken for different species. The last species of hawk known from the province is the rare stray Mississippi kite (Ictinia mississippiensis), distinctive with its long pointed wings and notched tail.