The Snowy owl is a large and powerful bird. It is one of the largest species of owl, and in North America, it is on average the heaviest owl species. The adult male is virtually pure white, but females and young birds have some dark spots; the young are heavily barred, and dark spotting may even predominate. Thick plumage, heavily feathered taloned feet, and coloration render the Snowy owl well-adapted for life north of the Arctic Circle.
Snowy owls are native to Arctic regions in North America and Eurasia. Some birds remain in the breeding area year-round if conditions allow while others winter south through Canada and northern Eurasia. Snowy owls inhabit open tundra and can also be found in coastal dunes and prairies, open moorland, meadows, marshes, and agricultural areas.
Most owls sleep during the day and hunt at night, but Snowy owls are active during the day, especially in the summertime. Outside of the breeding season, these birds lead a solitary life. They are often seen resting on the ground or on mounds, rocks, fences, and buildings. Snowy owls are opportunistic hunters and a variety of prey species may vary considerably, especially in winter. Most of their hunting is done in the "sit and wait" style; prey may be captured on the ground or in the air, or fish may be snatched off the surface of bodies of water using their sharp talons. Snowy owls, like other carnivorous birds, swallow their small prey whole. Strong stomach juices digest the flesh, while the indigestible bones, teeth, fur, and feathers are compacted into oval pellets that the bird regurgitates 18 to 24 hours after feeding. Snowy owls are shy and generally silent. Their calls are varied, but the alarm call is a barking, almost quacking krek-krek; the female also has a softer mewling pyee-pyee or prek-prek. The song is a deep repeated gahw. They may also clap their beak when threatened or disturbed. While called clapping, it is believed this sound may actually be a clicking of the tongue, not the beak.
Snowy owls are carnivores. They feed on a wide variety of small mammals such as lemmings, meadow voles and deer mice, but will also take advantage of larger prey. Some of the larger mammal prey includes hares, muskrats, marmots, squirrels, rabbits, raccoons, prairie dogs, rats, moles, and entrapped furbearers. Birds preyed upon include ptarmigan, ducks, geese, shorebirds, pheasants, grouse, coots, grebes, gulls, songbirds, and even other raptors, including other owl species.
Snowy owls are generally monogamous and often mate for life; however, polygynous behavior may occur occasionally and males may mate with two females that may nest about a kilometer apart. The breeding season is usually from May to June. During this time the male performs courtship display to attract a female or to strengthen an existing pair bond. Snowy owls nest on the ground, building a scrape on top of a mound or boulder. They choose a site with good visibility, such as the top of a mound with ready access to hunting areas and a lack of snow. Gravel bars and abandoned eagle nests may also be used. The female scrapes a small hollow before laying the eggs. Depending on the amount of prey available, clutch size ranges from 3 to 11 eggs, which are laid singly, approximately every other day over the course of several days. Hatching takes place approximately 5 weeks after laying, and the pure white helpless owlets are cared for by both parents. Both the male and the female defend the nest and their young from predators, sometimes by distraction displays. Owlets begin to leave the nest and crawl around the area 14-26 days after hatching and fledge 7 to 8 weeks later. Reproductive maturity is usually reached at 2 or 3 years of age.
Snowy owls are not considered endangered however, human activities pose the main threat to these beautiful birds. Among these are collisions with power lines, wire fences, and vehicles. Snowy owls also suffer from illegal hunting and are also often caught in fishing equipment.
According to the IUCN Red List, the total Snowy owl population size is around 28,000 mature individuals. The European population consists of 700-2,300 pairs, which equates to 1,400-4,600 mature individuals. Overall, currently, Snowy owls are classified as Least Concern (LC) on the IUCN Red List but their numbers today are decreasing.
Snowy owls play an important role in their ecosystem; they control populations of a wide range of small rodents which is especially useful in agricultural regions.