They don’t build shelters, and they don’t live in houses, so how do they survive cold harsh climates? You may even be surprised to hear that polar bears can swim, and they can spend a greater part of their day on sea ice. For this reason, polar bears are in the marine animals class, being one of the few mammals to have this honour. These interesting animals have adapted over the years to survive in their own habitat, the Arctic region of our planet. Here are some interesting facts about these animals.
Your first guess may be that the polar bear has a thick white furry coat, with plenty of stored fatty deposits to help them survive the cold. This is true. An adult male polar bear, also called a “boar”, can weigh anywhere from 350 to 700 kilograms, or 770 to 1540 lbs. Adult females, called a “sow” are half that size, yet they also survive the cold climate. Did you know that the polar bear is related to the common brown bear that is present in most regions of North America? The polar bear has evolved over the years, way earlier than humans ever took that first step onto our continent. Their body features have adapted to the cold climate up north. The white fur may be have also evolved, protecting them from human hunters who would have difficulty in seeing white fur against a white snowy landscape.
Polar bears are from the Ursidae bear family and have evolved from the brown bears starting about 38 million years ago. The actual polar bear is believed to have been around in its current form since about 4.2 million years ago, but the oldest fossil found has been about 130,000 years old. It’s believed that a family of brown bears got separated and stuck on a glacier during the Pleistocene era. It’s quite amazing this bear family evolved and survived such a harsh climate. Since humans only occupied part of the Arctic, these animals thrived and their population grew. Polar bears have no desire to travel south, as they’d find warmer climates too uncomfortable for them. And also, they’d be hesitant, due to higher numbers of human population in warmer climates.
Bears are the only marine animal that can run quickly on land too. They have big powerful limbs that can cover several kilometres in one trip. They do prefer the icy water and hopping from ice block to ice block. This is where they hunt for their main food source, seals. They don’t eat the seal meat though, instead, focusing on the blubber, or the seals’ fatty deposits. They eat about 4.4 pounds of fats per day. Seals do migrate according to weather conditions, and that means that their predators move with them too. This is why you’ll rarely see polar bears right up near the North Pole. Seals would rather have an easier source of food. Like most land mammals, drinking salty sea water won’t help them to survive but only make them thirstier. But they still need hydration, and for this reason, their bodies have adapted. When polar bears eat seal blubber, their bodies produce water through their metabolism, which keeps them hydrated. Polar bears will build up their fatty deposits between the months of April to July, in preparation for another cold winter ahead. Polar bears have no desire to travel south, as they’d find warmer climates too uncomfortable for them. And also, they’d be hesitant, due to higher numbers of human population in warmer climates.
The most common time for them to mate is in April to May. A female will seek shelter in a cave, or else create a snow cave which is called a “den”. New cubs are born from December to January. A pregnant female polar bear naturally needs more energy during the 7 to 8 months she is pregnant. During this time her body will burn up stored body fat. In some instances, she could lose up to 40% of her body mass. When the cubs are born, they have no fatty layer inside their bodies, and their fur is short. For this reason, they must stay in the den and beside their mother to keep warm. During this time, they drink their mother’s milk, which is naturally warm and contains up to 35% of fats. The cubs are nursed until 2 years old, though some are weaned at one year. During this time, their mothers teach them the survival skills they need, as well as how to hunt. It’s amazing how polar bears have adapted to a much colder climate than most other animals on this planet. It helps to learn as much as we can about them, so that they won’t go extinct due to climate change or human encroachment. Seals do migrate according to weather conditions, and that means that their predators move with them too. This is why you’ll rarely see polar bears right up near the North Pole. Seals would rather have an easier source of food. Like most land mammals, drinking salty sea water won’t help them to survive but only make them thirstier. But they still need hydration, and for this reason, their bodies have adapted. When polar bears eat seal blubber, their bodies produce water through their metabolism, which keeps them hydrated. Polar bears will build up their fatty deposits between the months of April to July, in preparation for another cold winter ahead. Polar bears have no desire to travel south, as they’d find warmer climates too uncomfortable for them. And also, they’d be hesitant, due to higher numbers of human population in warmer climates.
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