The polar bear is the largest land carnivore in the world, making its home in the harsh, frozen north across the icy landscapes of the Arctic Ocean. To survive in this extremely cold environment, the polar bear has evolved into a powerful, specialized predator. It depends entirely on the sea ice as a platform for its life, spending most of its time hunting to maintain its massive size and energy reserves.
The Polar Bear’s Favorite Meal
The polar bear’s diet focuses almost entirely on seals. These marine mammals are the most important food source because they provide the specialized nutrition the bears need to survive. They primarily hunt smaller ringed seals and larger bearded seals.
Seals are necessary because they have a thick layer of fat, called blubber, just beneath their skin. Blubber provides twice as much energy per gram as muscle meat. A polar bear needs this rich food to build up its own fat reserves, which act as insulation against the Arctic cold and allow it to go for long periods without eating.
During successful hunts, a bear may eat the blubber and skin first, sometimes leaving the rest of the seal for scavengers like foxes. This preference highlights the importance of fat, which fuels the bear and allows it to survive times of food scarcity. A single adult bear can consume over 100 pounds of seal blubber in one meal.
Clever Hunting Techniques
The polar bear uses its intelligence and patience to capture its prey on the ice. One of its most common methods is called “still hunting.” This involves finding a seal’s breathing hole in the ice, known as an aglu, which the seal keeps open all winter long.
The bear uses its extraordinary sense of smell to locate these small openings, sometimes detecting them from over half a mile away. Once a hole is found, the bear crouches down silently and waits until a seal comes up for a breath of air. When the seal surfaces, the bear quickly reaches in with a powerful paw or its jaws to pull the heavy animal onto the ice.
Another effective technique is hunting for seal pups in their snow dens, called lairs. The mother seal digs these small caves under the snow to protect her newborn pup from the cold. The polar bear smells the pup hidden beneath the snow and uses its strength to crash through the roof of the lair. Catching these young pups in the spring is a particularly important time for the bears to build up their fat stores.
Snacks When Seals Are Hard to Find
When the sea ice melts in the summer, the seals move out into the open water, making them nearly impossible to catch. This forces the polar bear to spend time on land, relying on the fat reserves it built up during the winter and spring. If their reserves run low, they will look for other food sources, but these alternatives are not as nutritious as seal blubber.
These secondary foods include items like bird eggs and young birds, which they find in coastal nesting colonies. They may also eat berries, grass, or small rodents on the tundra. Occasionally, a bear will scavenge on the carcass of a large animal, like a dead whale or walrus that has washed ashore.
While these items help the bears survive lean periods, they do not provide enough energy to sustain the polar bear’s massive body size long-term. These snacks are simply a way to pass the time until the sea ice returns, allowing the polar bear to get back to its specialized hunt for high-fat seals.