Snowy Owl (Bubo scandiacus): Facts, Habitat, Diet and Status

Name and relatives

The snowy owl was named by Carl Linnaeus in 1758. For most of the 20th century it was placed in its own genus as Nyctea scandiaca, because its white plumage and Arctic lifestyle seemed so different from other owls. DNA studies later showed that it is closely related to the eagle-owls and horned owls of the genus Bubo, including the great horned owl of the Americas and the Eurasian eagle-owl, and it is now called Bubo scandiacus. No subspecies are generally recognized.

Other names include Arctic owl, polar owl and white owl. Its scientific name means “owl of Scandinavia”.

What does a snowy owl look like?

The snowy owl is the only owl that is mostly white. It has a rounded head with no visible ear tufts, bright yellow eyes and a black bill almost hidden in feathers. The legs and toes are covered in long, dense white feathers, giving the feet a furry look; the toe feathers are the longest of any owl.

Males and females look different. Adult males are almost pure white, often with just a few small brown spots, and they tend to get whiter with age. Females are heavily marked with dark brown bars and spots across the crown, back and breast, leaving the face and front of the neck white. Young birds of both sexes look like dark females. To find out why, see Why are snowy owls white?

In flight a snowy owl looks large and broad-winged, with steady, powerful wingbeats. On the ground it often looks like a lump of snow or a pale rock.

How big is a snowy owl?

The snowy owl is one of the largest owls in the world by weight and the heaviest owl in North America. Females are clearly larger than males.

Much of the bulk is feathers. The plumage is so thick that the snowy owl is one of the best-insulated birds in the world, able to stay warm at temperatures far below freezing.

Habitat and range

Snowy owls breed on the treeless Arctic tundra, mostly north of about 60° N: in Alaska, northern Canada, Greenland, the far north of Scandinavia and across northern Russia. They choose open, rolling ground with low mounds or ridges, where they can watch for prey and danger. They share the tundra with lemmings, Arctic foxes, caribou and geese.

In winter many move south. They turn up in places that resemble the tundra: prairies, farmland, coastal dunes, beaches, salt marshes, frozen lakes and even airports. Some adults stay in the Arctic all winter, hunting along open water in sea ice. For the full picture, see Where do snowy owls live?

In Europe snowy owls are rare. Outside the far north of Norway, Sweden, Finland and Russia, they appear only as occasional winter visitors. A pair famously nested on the island of Fetlar in Shetland, Scotland, from 1967 to 1975, the only regular breeding record in the British Isles.

What do snowy owls eat and how do they behave?

In the breeding season the snowy owl is a lemming specialist. Brown and collared lemmings make up most of its summer diet, and a single owl may eat more than 1,600 lemmings in a year. When lemmings are scarce, it switches to voles, Arctic hares, ptarmigan, ducks, seabirds and other birds, and it will scavenge carcasses.

Snowy owls usually hunt from a low perch or a rise in the ground, watching and listening, then gliding low to grab prey in their feathered talons. They can also catch birds in flight and take ducks from open water. Small prey is swallowed whole, and the indigestible fur and bones are coughed up later as pellets. Compare their menu with other species in What do owls eat?

Daytime hunting, calls and winter territories

Unlike most owls, snowy owls are often active by day. In the Arctic summer the sun never sets, so they hunt whenever prey is moving. In winter they often hunt at dawn and dusk and spend much of the day resting on the ground or on a low perch.

They are mostly silent away from the nest. On the breeding grounds males give a deep, booming hoot that carries for kilometers across the tundra, and both sexes bark, hiss and clack their bills when disturbed.

In winter some females hold feeding territories for weeks, while males tend to move around more. Banding studies show that some owls return to the same wintering sites year after year.

Nomadic breeding and lemming years

The snowy owl’s life is tied to the rise and fall of lemming populations. In many parts of the Arctic, lemming numbers rise and crash every few years. Snowy owls are nomadic: instead of returning to the same nest site, they search widely each spring and settle where lemmings are plentiful. Satellite tracking in the Canadian Arctic has shown females flying more than 1,000 km (620 mi) in spring while searching for a place to nest.

The nest is a shallow scrape on a raised mound, made by the female. Clutch size depends on food: in poor years many owls do not breed at all, while in a good lemming year a female may lay up to 11 eggs or more. The eggs are laid about two days apart and incubated by the female for about 32 days, so the chicks hatch over a period of days and differ greatly in size.

The male brings food to the female and chicks and defends the nest boldly, diving at Arctic foxes, wolves, skuas and even people. Snow geese and other birds sometimes nest close to snowy owls, gaining protection from foxes. The young leave the nest at about three weeks old, before they can fly, and hide among the tundra hummocks; they fly at about seven weeks and stay with their parents into autumn.

How long do snowy owls live?

Snowy owls live a long time for birds. Many probably live around 10 years in the wild, though young birds face high losses in their first year. The oldest known wild snowy owl was banded in Massachusetts and found in Montana 23 years and 10 months later. In captivity, snowy owls have lived to about 28 years.

Predators and threats

Adult snowy owls have few natural predators. Eggs and chicks are taken by Arctic foxes, wolves, skuas (jaegers) and ravens, and adults are occasionally killed by large eagles.

Human-related threats include:

• Climate change, which disrupts snow conditions and the lemming cycles the owls depend on.
• Collisions with vehicles, aircraft, fences and power lines, especially in winter in farmland and around airports.
• Electrocution on power poles.
• Shooting, now illegal in most of the range, though some subsistence and illegal hunting still occurs.

Conservation status

The IUCN lists the snowy owl as Vulnerable, a status it has held since 2017, with a decreasing population. For decades the world population was estimated at more than 200,000 birds, but studies in the 2010s showed this was far too high. Current estimates suggest perhaps 28,000 breeding pairs or fewer, and North American surveys indicate steep declines since the 1970s. Read more in Are snowy owls endangered?

Counting snowy owls is unusually hard, because they breed in remote places, move unpredictably and skip breeding in poor years. Researchers now use satellite tracking and coordinated surveys across the Arctic to improve the estimates.

Winter irruptions

Every few years, large numbers of snowy owls appear far south of their usual winter range. These events, called irruptions, usually follow a summer with plenty of lemmings, when many chicks survived. Most of the owls that travel far south are young birds in their first winter, pushed out by competition with adults.

The winter of 2013–2014 brought one of the largest irruptions on record in eastern North America, with snowy owls reported from the Great Lakes to the Atlantic coast and as far south as the Carolinas. That event inspired Project SNOWstorm, a research program that has since fitted dozens of owls with tracking devices to follow their movements.

Contrary to popular belief, most owls seen during irruptions are not starving. Studies of birds caught in winter found that many were in good condition, and most deaths recorded were caused by collisions rather than hunger.

Snowy owls and people

For Arctic peoples the snowy owl has long been a familiar bird; its Inuktitut name, ukpik, gave rise to the Canadian souvenir doll called Ookpik. An engraving of a pair of snowy owls with a chick in the Trois-Frères cave in southern France dates from the last Ice Age, when snowy owls lived much farther south in Europe.

Today the snowy owl is the official bird of Quebec and a favorite of winter birdwatchers. Its fame grew enormously through Hedwig, Harry Potter’s owl. Snowy owls that turn up near cities attract crowds, and birders encourage people to watch from a distance so that tired young owls can rest and hunt undisturbed. Other North American species are covered in our guide to owls of North America.