The snowy owl is a majestic predator of the far north, instantly recognizable by its striking white plumage, which provides camouflage in its Arctic home. This large owl inhabits the vast, treeless expanse of the circumpolar tundra, enduring some of the planet’s most extreme conditions. Survival depends entirely on its ability to find and consume sufficient calories. The owl’s diet directly reflects the Arctic ecosystem’s cycles, shaping its behavior, breeding success, and migration patterns.
The Main Staple: Lemmings and Voles
The snowy owl’s diet is overwhelmingly dominated by small rodents, specifically lemmings and voles, which form the energetic foundation of its life on the tundra. During the breeding season, lemmings can constitute well over 70% of the owl’s total prey items, sometimes exceeding 90% in certain regions. The owl’s reproductive success is almost entirely tied to the availability of these rodents, which are subject to dramatic population fluctuations.
Lemmings experience a well-documented boom-and-bust cycle, with their numbers peaking approximately every three to five years. When the lemming population is high, snowy owls will lay larger clutches of eggs, sometimes numbering as many as 14, and successfully fledge a greater number of young. Researchers have found nests surrounded by caches of dead lemmings, collected by the male owl to provision the female and chicks.
This direct ecological link is the primary driver of the snowy owl’s nomadic behavior and its southward movements, known as irruptions. A successful breeding season fueled by a lemming boom produces an abundance of juvenile owls, which disperse south during their first winter to find new hunting grounds. Conversely, when lemming numbers crash, the owls may not attempt to nest at all, as the sustained caloric intake required to raise a brood is unavailable.
Dietary Flexibility: Secondary Prey Items
While lemmings and voles are preferred, the snowy owl is an opportunistic hunter that relies on dietary flexibility when its primary prey becomes scarce. This adaptability allows the bird to survive during the lean years of the lemming cycle or when it migrates away from the Arctic breeding grounds. Secondary mammalian prey includes arctic hares, rabbits, various mice, and ground squirrels, which provide a larger, albeit less frequent, meal.
Birds represent another significant component of the diet, particularly waterfowl and other arctic species. The owl will readily take ducks, geese, gulls, and shorebirds, often catching them directly on the water or in flight. The willow and rock ptarmigan, which remain in the Arctic year-round, are also regular targets, especially during winter.
Occasionally, snowy owls will feed on fish taken from the surface of the water or on carrion, such as the remains of seals or larger mammals. These secondary food sources sustain the adult owl, but they cannot support the high energy demands of a successful breeding season like a dense lemming population can.
Unique Hunting Strategies in the Arctic Tundra
The open, treeless landscape of the tundra dictates a unique set of hunting strategies for the snowy owl, distinguishing it from most forest-dwelling species. Due to the lack of trees, the owl employs a low-perch hunting technique, utilizing any elevated point such as a rock, ridge, or small mound to scan the terrain. From these vantage points, the owl uses its exceptional visual acuity to spot prey movement from long distances, sometimes over 300 feet away.
Unlike many of its relatives, the snowy owl is often diurnal, or active during the day, a necessary adaptation given the continuous daylight of the Arctic summer. It also relies heavily on its acute hearing, which is enhanced by asymmetrical ear openings, allowing it to pinpoint the exact location of small rodents moving beneath a layer of snow. The owl executes a swift, silent flight, often described as a “wallop,” pouncing directly onto the prey with its powerful talons.
When flying low over the ground, the owl can employ a slow, quartering flight pattern, hovering briefly before dropping down to capture an animal. This combination of sight and sound hunting, executed with stealth and precision, allows the snowy owl to efficiently exploit the limited food resources scattered across its vast Arctic territory.