The snowy owl (Bubo scandiacus) is a raptor recognized by its striking white plumage, which provides camouflage across its native Arctic tundra habitat. As one of the largest owl species, it sits near the top of the food web in northern latitudes. Its specialized diet, relying heavily on lemmings, and its size mean a healthy adult has few consistent natural predators. Vulnerability is highest early in life.
Predators of Juvenile Snowy Owls
Most predation risk targets the nest, where eggs and flightless young are highly vulnerable. Since the owls build their nests as a simple scrape on the ground, they are exposed to terrestrial mammals. The Arctic Fox represents the single most significant nest predator, often successfully raiding the nest when the parents are distracted or away hunting.
Smaller, opportunistic predators include mustelids, such as ermine and weasels, which can slip past the parent owls’ defense. Avian scavengers like Skuas and Jaegers also capitalize on unattended eggs or young chicks. The female owl fiercely defends her nest site, often flying at and striking intruders, but these smaller, faster predators can sometimes breach the perimeter.
These nest predators rely on stealth and speed to exploit moments when one or both parents are absent. The abundance of these smaller carnivores and opportunistic birds means that nest failure due to predation is common.
Rare Threats to Mature Snowy Owls
A healthy, full-grown snowy owl is rarely preyed upon, which is typical for a top-tier predator in its ecosystem. Predation events involving adults are usually incidental, occurring when an owl is injured, starving, or caught completely by surprise. Large avian raptors, which may compete with the snowy owl for territory or prey, occasionally pose a threat.
Powerful birds like the Golden Eagle or the Gyrfalcon have been documented in conflicts with snowy owls. These encounters often happen during territorial disputes or over a contested carcass, sometimes resulting in the death and consumption of one bird. Terrestrial carnivores such as the Gray Wolf or wolverines may also opportunistically attack a grounded or distracted adult owl.
These instances are uncommon because the snowy owl is a powerful, heavy bird capable of vigorous self-defense. Any predator attempting to take an adult faces a high risk of injury from the owl’s sharp talons. A mature snowy owl is more likely to die from other causes than from a successful, targeted attack.
Non-Predatory Causes of Mortality
The leading causes of death for the species are non-predatory. Starvation, or emaciation, is a substantial natural cause of death, particularly during years when lemming populations are low or during the winter migration, known as an irruption. Young, inexperienced owls are especially vulnerable to food scarcity.
During irruptive years, when large numbers of owls move south into temperate regions, human-related mortality becomes the dominant factor. Collisions with vehicles and aircraft are frequently reported as the cause of death for these migrating individuals. Necropsy data on irruptive owls shows that these traumatic injuries are more common than starvation.
Electrocution from perching on power lines is a risk in human-altered landscapes. Owls may also sustain fatal injuries during aggressive territorial fights with other snowy owls, or while attempting to hunt large or difficult prey. These factors collectively contribute to a higher rate of mortality than direct predation in the adult population.