Welcome to the Birds of North America Online!
Welcome to BNA Online, the leading source of life history information for North American breeding birds. This free, courtesy preview is just the first of 14 articles that provide detailed life history information including Distribution, Migration, Habitat, Food Habits, Sounds, Behavior and Breeding. Written by acknowledged experts on each species, there is also a comprehensive bibliography of published research on the species.
A subscription is needed to access the remaining articles for this and any other species. Subscription rates start as low as $5 USD for 30 days of complete access to the resource. To subscribe, please visit the Cornell Lab of Ornithology E-Store.
If you are already a current subscriber, you will need to sign in with your login information to access BNA normally.
Subscriptions are available for as little as $5 for 30 days of full access! If you would like to subscribe to BNA Online, just visit the Cornell Lab of Ornithology E-Store.
Editor's Note 01/06: Formerly placed in genus Nyctea -- based on plumage, osteological (skull) characters, and DNA -- this species is now (based on new genetic evidence) considered closely related to the Bubo owls and nested in that genus. Future revisions of this account will reflect this change.
This large, northern circumpolar owl breeds in open terrain from near tree line to the edge of polar seas, wintering regularly south to the northern U.S. and sporadically beyond. A nomadic species and often unpredictable migrant, its movements are thought to relate to the variable abundance of its main prey species, lemmings. As a winter migrant, it is more regular and abundant in the northern Great Plains than it is to the east, west and south of there. It nests on windswept hummocks and boulders in the arctic barrens, producing large clutches and up to a dozen young per nest where food is abundant. Where food is scarce, it may refrain from breeding for a year or more.
Differing from most owls in being largely diurnal, the Snowy Owl hunts in all weather during winter and the continuous light of arctic summer, at times consuming more than 1,600 lemmings a year. Generally monogamous and territorial, it is often vocal and aggressive in defense of territory and young, sometimes striking humans and even wolves that stray near nests. Adult males are noticeably smaller and paler than adult females, immatures being the most heavily marked as a rule.
This owl is probably the oldest bird species recognizable in prehistoric cave art. Audubon’s 1829 painting of a pair of Snowy Owls depicts the dimorphism in size and plumage of the two sexes. Although these birds often hunt by day, Audubon included them in the only nocturnal scene that he painted.