Complete Polar Bear Facts

Polar bears together with other polar bears

Friends Polar bears don't tend to have many friends. They spend most of their lives alone, and are content that way. Sometimes they will share food with another bear instead of fighting for it if there is enough. Of course cubs will stay with their mothers until they are old enough to be on their own, in two or three years.

	Playfighting In some places of the world, like near Churchill, Manitoba on Hudson Bay in Canada, polar bears will gather in the fall to wait for the ocean to start to freeze. Dozens of polar bears can gather in one area, patiently waiting for the weather to cool off enough for the bay to freeze. Sometimes they will playfight to stretch their muscles after a lazy summer and be ready for the new hunting season. This playfighting will also help them learn how to fight, and to find out which other polar bears are strong or weaker than they are. Usually only the males will playfight. Serious fighting Polar bears will only fight when there is something to fight over, and since they don't have territories of their own, they will usually only fight over food or a mate. A fight may start if one bear tries to steal food from another bear. Fights are usually a last resort, because no polar bear wants to risk an injury that could prevent them from hunting. Even the winner of a fight might get a broken jaw, which could prevent them from eating or hunting properly.

Momma bears and Poppa bears Mating - Polar bears mate in April and May, when spring is in the air. It is one of the few times that a sow will spend time with a boar. Sows will only produce an egg when they don't have cubs and a boar is near. Polar bears find each other by gathering at the best seal hunting areas. A boar has been seen tracking a sow's paw prints for over 100km (60miles). Scientists are not sure how a boar knows to follow the paw prints but some think that a scent is given off from the sow's paws, and that is what the boar follows Other scientists think that the smell of the sow's pee is what the boar will follow. Several males will usually follow one female, but only the biggest and strongest boar will mate with the sow. This is when serious fights can happen between males. These fights can break teeth and leave scars. Usually one bear will give up before things get too serious. It is better to run away, than get hurt or killed. Boars and sows will stay together for about a week and mate several times. That is the only part the boar plays as a poppa bear. Sows are usually ready to mate when they are 4 years old. Males may be ready to mate when they are 6 years old, but they are usually too small to scare off other bears, and may not actually mate until they are 8 or 10 years old.
Polar Bear Pregnancy - When a sow is pregnant, she must gain lots of weight; at least 200kg (440lbs). She has several months to put on the weight. If she puts on enough weight, the fertilized egg will start to develop. Pregnant sows need this extra weight for the energy it will give them to raise their cubs. One sow was caught in the fall and weighed only 95kg (210lbs), which is the size of a big person, but very small for a polar bear. She was released and was caught again the next spring when she weighed 450kg (990lbs)! Can you imagine adding 355kg (780lbs) to you? If the sow wasn't able to hunt enough seals to put on the 200kg she needs to keep her and her cubs healthy, the egg doesn't develop and she is no longer pregnant. When all the other bears are thinking about going out to start hunting seals in October and November, the pregnant sows go into a den to hibernate. It is a very light hibernation, but her heart rate drops from 46 beats per minute to 27. While they sleep for a couple months, they slow their whole body down, and don't even go to the bathroom. Their bodies can recycle some of their own waste.
	Being born - The cubs are born in late December or early January while their mother sleeps. Usually the mother gives birth to two cubs. The tiny cubs are about the size of a squirrel, and weigh about the same as a brick of butter (600g,21oz). Boys cubs are born a little larger than the girls. They have claws when they are born which help them comb through all their mothers fur and find the nipple to drink from. The cubs are covered in a fine hair and stay warm by sleeping between their mother's legs and getting their energy from their mother's milk. After about a month, the cubs are crawling around; after six weeks their eyes open and their teeth will be out soon; after ten weeks the cubs are ready to leave the den with their mother. New cubs are called coys, which stands for Cub Of the Year, which means this year's new cub.
Growing up - During their first year the coys stay close to their mother. The next year, when they have their first birthday, they are just called cubs and will wander a little further from their mother. Normally cubs will stay with their mother for two and half years, but in the far north, they will stay an extra year. After two and a half years, the cubs are so big, it can be difficult to tell which bear is the mother and which is the cub. Part of the reason the cubs grow up so fast is because of the rich milk their mother produces. Sows feed their cubs sitting up, which allows them to look around while the cubs get their meal. Polar bear milk contains 30-40% fat. Human milk is about 4% fat and the milk that we buy at the store usually has about 2% fat in it. Although cubs can nurse from their mother for over two years, they will also start eating solid food as soon as their mother catches something. During the time they spend with their mother, polar bears must learn all the skills they will need to survive. Everyday is a school day for the cubs. They have to learn what to eat, where to find it, how to catch it and how to avoid all the dangers that might face them. One out of every two cubs die in their first two years, so they must be careful and learn quickly if they are to live.
On their own - After about two and a half years it is time for the cubs to go off on their own. Two and a half year old cubs are almost as big as their mother. When the mother is ready to mate again, she chases off her cubs so that they can start their own lives. Brothers and sisters may stay with each other for a little while once they have left their mother. The bear on the left is the cub and will leave her mother soon.