Snowy owl

Snowy Owl
Scientific classification
Kingdom Information
Domain	Eukaryota
Kingdom	Animalia
Subkingdom	Bilateria
Branch	Deuterostomia
Phylum Information
Phylum	Chordata
Sub-phylum	Vertebrata
Infraphylum	Gnathostomata
Class Information
Superclass	Tetrapoda
Class	Aves
Sub-class	Neornithes
Infra-class	Neoaves
Order Information
Order	Strigiformes
Family Information
Family	Strigidae
Sub-family	Striginae
Genus Information
Genus	Bubo
Species Information
Species	B. scandiacus
Population statistics

The snowy owl (Bubo scandiacus) is a bird of prey from the family Strigidae, and found throughout much of the Arctic tundra. Regarded for a long time as the only species of the genus Nyctea and therefore considered taxonomically isolated from the other species of owls, recent molecular studies have shown that it belongs to the genus Bubo, and is closely related to the great horned owl (Bubo virginianus). The external differences, such as the white plumage color and the feathered feet and toes, can be explained as adaptation to the arctic habitat.

Description

The snowy owl is large, nearly as large as the Eurasian eagle owl (Bubo bubo). Adult birds have a length of 21.6 to 25.9 inches, a wingspan of 57 to 61.8 inches, and weigh between 3.52 and 5.5 pounds; females are slightly larger than males.

The plumage is all white marked by brownish or black barring on individual feather tips. Adult females show a heavy amount of these bars; in contrast, adult males are nearly all-white. The face and upper portion of the chest on both is white. The black beak is mainly covered by dense, fine white feathers. The iris of the eyes is golden yellow. Similar to other members of genus Bubo, snowy owls also have ear tufts, but they are markedly less pronounced and are rarely erected. The feet and toes are tightly feathered in dense, snowshoe-like feathers, which serve as heat insulation and prevent the owl from sinking into the snow.

Snowy owls are very silent outside the brewing season. During the breeding season, on the other hand, the male emits a loud, rough croaking and a deep barking "hu", which is used to attract females and can be heard on the tundra over several miles. During this time, the female occasionally makes a croak, which is loud, but much quieter than the male. The birds calls also include hissing sounds, with which the youngsters use on the parent birds for food, cackling "ka ka ka" calls as warning calls, and a mule-like "kjaa" call if disturbed during the breeding.

Range and habitat

Snowy owls have a circumpolar distribution and occur in the tundra areas of Iceland, Northern Europe, Siberia, Alaska, Canada and Greenland. The southernmost deposits, for example in Norway, are found in mountains. From 1967 to 1975, snow-owls brooded on the Shetland Islands.

The snowy owl is a so-called "survival migrant" within its range, that is, it will adapt to the available food supply. Their occurrence in an area is dependent on the fluctuations in the stocks of the lemmings, their main prey. In very cold, snowy winters, or after a collapse of the lemming population, snowy owls migrate southward to Central Russia, Central Asia, Manchuria and the northern United States; occasionally, they also come to the north of central Europe.

The snowy owl lives on clear terrain north of the treeline in the high Arctic. In the Arctic they overwinter in wind-swept, snow-cleared areas of the tundra; in Scandinavia mainly in the mountains. Breeding areas are small patches of elevated ground, in areas which are free of snow early. Owls that have migrated southward often stay and hunt on agricultural land.