Polar bears are large carnivores adapted to life in the Arctic, making them iconic symbols of this harsh environment. As apex predators, their survival depends on their ability to hunt in frozen landscapes. These powerful mammals navigate their icy domain, relying on specialized skills to secure energy-rich prey.
Primary Prey
Polar bears primarily hunt seals, crucial for their diet due to high fat content. Ringed seals are the most common prey, providing significant nutritional value from their abundance and blubber. Bearded seals also contribute substantially, offering rich fat reserves despite being larger and less numerous.
While seals are their main food source, polar bears are opportunistic hunters. They may hunt young walruses, beluga whales, and narwhals, especially when vulnerable. Additionally, polar bears occasionally prey on birds, their eggs, or scavenge carrion like whale carcasses, particularly when seal hunting is challenging. However, these alternative food sources do not offer the same caloric density as seals.
Hunting Environment
The primary hunting ground for polar bears is the Arctic sea ice, which serves as a platform for their predatory activities. This ice-covered marine environment allows them access to their prey, primarily seals, and supports their unique hunting strategies. Features of the sea ice, such as ice floes, pressure ridges, and leads (cracks in the ice), are important as they create access points for seals to surface.
Polar bears are highly dependent on this sea ice, traveling across it in response to seasonal changes. While they can hunt in open water or on land, these methods are less efficient and less common. Ongoing changes in sea ice extent and thickness, including earlier spring retreat and later autumn formation, directly impact the time polar bears have to hunt effectively.
Hunting Strategies
Polar bears employ a variety of hunting techniques, often leveraging their keen senses. Their acute sense of smell is a primary tool, allowing them to detect seals from great distances—sometimes over 32 kilometers away on open ice or more than a kilometer through a meter of snow. This sense helps them locate breathing holes, seal lairs, or seals resting on the ice.
Still-hunting is a common and energy-efficient strategy. A polar bear waits patiently by a seal’s breathing hole, remaining motionless for hours or even days with its chin on the ice. When a seal surfaces, the bear strikes quickly, using its powerful paws and claws to pull the seal onto the ice and deliver a fatal bite to the skull.
Another technique involves stalking and ambushing seals resting on the ice. The bear slowly and stealthily approaches, often using snowdrifts or ice formations for cover, keeping its profile low. Once within range, about 6 meters, the bear charges rapidly to capture the seal before it can escape into the water. Bears may also position themselves downwind to prevent their scent from alerting prey.
During the spring pupping season, polar bears specifically target seal birthing lairs hidden under the snow. Using their strong sense of smell, they locate these snow dens, which can be over a meter deep. They then smash through the ice and snow with their front paws to access the pups. Larger bears are better equipped for breaking into these lairs.
While less common and efficient, polar bears can pursue prey in open water. They may swim after seals or dive under the ice to approach them. This aquatic stalking can involve swimming stealthily and lunging from the water to attack seals on ice floes. Polar bears are also opportunistic scavengers, readily consuming carrion like beached whale carcasses, which can provide substantial nutrition.