Prairie falcon (Falco mexicanus).
R.J. Long (Saskatchewan Environment) SKCDC, 2001. Ecosystem image information system

Falcons are streamlined birds of prey with long pointed wings and long tails. During flight, wing beats appear rapid and shallow as the wings are designed for speed, not sustained soaring. All falcons belong to the order Falconiformes and the family Falconidae. There are five falcon species found in Saskatchewan: American kestrel (Falco sparverius), merlin (F. columbarius), prairie falcon (F. mexicanus ), peregrine (F. peregrinus) and gyrfalcon (Falco rusticolus). Falcons do not build their own nests, and females are larger than males. They possess a tomial tooth, or tooth-like structure on the upper beak which is used to dispatch their prey by dislocating their neck vertebrae.

The American kestrel is the most numerous, widespread and smallest of our falcon species. This colourful falcon is sexually dichromatic, i.e., the sexes differ in their colour patterns. Males have blue-grey wings and a rufous tail with a single broad black band, while the females have rufous tails and wings with black bars across their lengths. American kestrels hunt predominantly rodents in open areas. They are secondary cavity nesters and can be found breeding throughout the entire province. Merlins are slightly larger than kestrels. Prairie merlins are lighter in colour than merlins which nest in forested areas. Adult males have blue-grey backs and black-banded tails. Females and immature birds have dusky brown backs and brown tails with buff-coloured bands. Both sexes have cream-coloured underparts with light brown streaks and yellow legs. Merlins use abandoned crow and magpie nests in deciduous and coniferous trees throughout the province, and are also very common in cities in Saskatchewan. The merlin’s main food consists of small birds, and in urban areas they are particularly fond of house sparrows.

The prairie falcon is a crow-sized bird, with sandy-coloured back and tail which contrast with its creamy white underparts. The breast, belly, and legs are streaked with darker markings. At close range, its distinguishing mark is its white face with a narrow, dark “moustache.” In flight, its underside is whitish with a black patch under each wing at its base. Prairie falcons establish a nesting territory where there is a ledge or crevice on a cliff or embankment that faces open grassland areas, as in the southern badlands. The most common food item during the prairie falcon’s breeding season (summer) is the Richardson’s ground squirrel (Spermophilus richardsonii). In winter prairie falcons depend heavily on small passerine birds, but they will also eat other prey such as ducks, rabbits and hares, as well as small mammals such as mice.

The peregrine is one of the most widely distributed warm-blooded terrestrial vertebrate species. Indeed, the name peregrine means “wanderer,” and peregrines can be seen throughout Saskatchewan during the spring and fall migration periods. Peregrines have bluish-gray backs and whitish, grayish or buffy underparts with variable amounts of spotting and barring. Peregrines hunt a wide variety of other birds. Somewhat ironically, the best places to observe peregrines in Saskatchewan are in our larger urban centres of Saskatoon and Regina, as these provide ideal breeding habitat in the form of inaccessible cliffs (skyscrapers) and a ready supply of prey (mostly in the form of rock pigeons, Columba livia). Observing peregrines in these locations may diminish their image as a symbol of wilderness, but it does not detract from their amazing abilities as one of nature’s pre-eminent aerobatic performers.

The gyrfalcon, our largest falcon, is also the fastest falcon in level flight. Its colour is highly variable and can range from a dark slate-grey to white. Gyrfalcons typically nest on cliffs in the more remote areas of the Arctic and make their way into Saskatchewan during the late fall and winter months in search of prey. Often the birds seen in Saskatchewan are sub-adults. These large raptors can hunt a variety of prey, but are best adapted to kill other large birds such as ducks and grouse. At times, however, they will take rabbits and hares. As is to be expected with a bird of this size, and also given the nature of its preferred breeding habitat, it has never been a very common bird in Saskatchewan.

Rick Espie

Further Reading

Alsop, F.J., III. 2002. Birds of Canada. New York: Dorling Kindersley; Cade, T.J. 1982. The Falcons of the World. Ithaca, NY: Cornell University Press.