Hobbies And Interests
Diet
Polar bears are mostly carnivorous. The polar bear's diet is mainly composed of ringed seals. If there is a shortage of these seals, the polar bear may predate other seal species such as harp seals, bearded seals and harbor seals. More rarely, polar bears may kill and eat larger animals such as walruses and small whales. Occasionally, land animals such as caribou can also become prey if there is a shortage of the polar bear's preferred foods. Polar bears will also eat the carcasses of animals such as seals and walruses that they have not killed themselves. If there is little prey for the polar bear, they may eat vegetation such as berries and grass.
Predatory Behavior
Polar bears have several methods of hunting seals. One of these is to wait patiently by the top of the breathing holes that seals create in the ice above them when they are underwater. When a seal surfaces for air through the breathing hole, the polar bear uses its large front paws and sharp claws to deliver a blow to the seal and to drag it up through the hole. Polar bears are strong swimmers and they use this skill to swim beneath ice floes and disturb them, knocking any seal prey into the water to be killed. Polar bears may also dig into seal dens to kill and eat seal pups.
Fat Stores
Polar bears eat the fat from prey such as seals as soon as they are killed, allowing the bear to consume a large amount of calories in a short period of time. This is important because the smell of the carcass could attract another polar bear to compete for the food. Polar bears need to consume a great deal of energy to build their own fat stores which help to keep them warm and serve as emergency food supplies. When ice melts in the summer months, less prey is available and the polar bear survives on the energy from stored fat.
Feeding Young
Female polar bears ensure that they can provide enough milk to feed their young by going into hibernation while they are pregnant and while they nurse. At this time, a female polar bear may have to survive on her fat stores alone for around 8 months. After hibernation, she may continue to nurse her young by returning from her hunting trips. Some polar bear cubs can nurse for up to 18 months. Food availability impacts reproduction. If a female has not built up a sufficient store of energy, an embryo may not implant until the next year. Polar bears have larger litters if they have been able to build large stores of fat.