Though Snowy Owls have few predators, the adults are very watchful and well equipped to defend against any kind of threats towards them or their offspring. During the nesting season the owls regularly face arctic foxes and swift-flying jaegers as well as dogs, gray wolves and other avian predators. Humans are probably the most important predator of snowy owls. They must be very careful not to leave their eggs unattended. Males defend the nest by standing guard nearby while the female incubates the eggs and broods the young. Both sexes attack approaching predators, dive-bombing them and engage in distraction displays to draw the predator away from the nest. They also compete directly for lemmings and other prey with several predators, including rough-legged hawks, great horned owls, golden eagles, peregrine falcons, gyrfalcons, jaegers, glaucous gulls, short-eared owls, common ravens, wolves, arctic foxes, and ermine. Some species, such the snow goose, nest near snowy owl nests seem to benefit from the protection of snowy owls that drive competing predators out of the area.
Environmental conditions also cause local threats of food shortages, but their ability to be mobile permits them to move to areas were supplies may be more sufficient. Human activities probably pose the greatest danger to these birds, through collisions with power lines, fences, automobiles, or other structures that impose on their natural habitat. Now, Canadian provincial and territorial regulations have introduced prohibitions of killing of these birds in all parts of Canada, where they are most abundant, but the owls are still used for certain study programs.
This species is an extremely important component to the food web in the tundra ecosystem and during its visits to the south, the Snowy Owl may play a useful role in the natural control of rodents in agricultural regions