Of the 123 types of owls found in the world, the robust Snowy Owl of the North is one of the most beautiful. Snowy Owls (Nyctea scandiaca) breed on the arctic tundras of the world including here in Alaska. Many Snowy Owls winter where they nest, but those breeding in the northernmost regions, particularly where 24 hours of darkness occurs in winter, move during this period to the southern limit of their breeding range, which in North America takes them to southern Canada and across the northern part of the lower 48 states. Snowy owls are not regular migrants but tend to match their southern excursions to the population lows of the lemmings, about every four or five years. In many regions of the Arctic they breed mainly in years when lemmings are abundant and will fail to nest at all when lemmings are scarce. They also eat small mammals such as rabbits, hares, ptarmigan and ground squirrels. In coastal areas they my feed on birds such as ducks, geese, grebes and sometimes songbirds.
The Snowy owl is a very large bird measuring 22 to 27 inches with a wing span of about 5 feet. The female is larger and heavier than the male, as is the case with many large hawks and owls. The male is almost pure white and the female has white feathers which are tipped and barred with dark brown, making her appear much darker. A dense layer of down next to the skin insulates the entire body, including the legs and toes, which enables the bird to maintain a body heat of 100 to 104 degrees F in temperatures that may reach -40 to -60 degrees F. To overcome the wind chill factor, the owl faces the wind so that its feathers are pressed against the body or it may crouch behind a wind break such as a rock. Its light plumage provides good camouflage in its snowy environment.
The smooth, round head lacks the ear-like feather tufts characteristic of many owls. The yellow eyes are surrounded by feathers that grow from disk-shaped face bones. These disks serve as parabolic reflectors throwing sound waves to the ears located immediately below. Its acute hearing enables the Snowy Owl to hunt by sound in total darkness, when it cannot see. However, this owl is primarily diurnal, doing most of its hunting by day, of course, given the 24 hour daylight during the arctic summer nesting season. The eyes of owls are directed forward and do not move in their sockets. To look to the side or to follow a moving object, the bird swivels its head as much as 270 degrees, giving the impression that it will twist its head off. These highly developed eyes contain many light-gathering cells, many more than the human eye, and can spot tiny objects moving at a great distance.
In the years when the Snowy Owl winters farther south, it lives in open fields and on shorelines that are similar to the treeless tundra. It will perch on telephone poles, fence posts, buildings, wherever the view is unrestricted. Like most hawks and owls, the Snowy Owl is a loner when it is not breeding. Each bird stakes out a hunting territory, the size depending on how much prey is available. As early as February and March the owls that wintered farther south will start heading to their arctic breeding grounds. Most all of them are well on their way by April and that is the best time to see one here in the Interior, as it passes through on its way north. Their nesting habits depend on how many lemmings are available. In years of abundance they may lay up to 10 eggs to make up for lost production during lean years. The nest is simply a depression scraped in the ground by the female, with a few of her own feathers and a few pieces of grass or moss. It is located on a knoll or some vantage point giving a good view of the surrounding area. While she incubates the eggs her mate provides her food so she does not have to leave the nest in early May, when temperatures are below freezing and she must stay on the eggs to keep them warm.
In courtship, the male flies with deep, slow wingbeats, often carrying a lemming in his bill, landing near the female and leans forward with his wings raised to provide her the offering. Generally, these birds are shy and silent but when nesting they hiss and scream at intruders and will dive in defense of the nest. The female begins incubation when she lays the first eggs. Hatching takes from 32 to 33 days and laying continues into the brooding period. As a result large clutches may have chicks of many different ages and colors since the down changes from white, just after hatching to dark grey and nearly black at 10 days old. The chicks leave the nest when only two to three weeks old, long before they fly. The male faithfully feeds these young and also supplies the nest with food. Fledging occurs at eight weeks when the dark feathers are replaced by flight feathers.
Formerly, many of these magnificent birds were shot during their southward invasions in winter. Most North American breeding areas are remote from effects of human disturbance (other than oil development) but in northern Europe the bird has declined in parts of its breeding range. Fortunately, an ever-increasing number of people are learning to enjoy this bird, along with many other creatures and prefer shooting it with cameras instead of guns.