THE LIFE OF THE POLAR BEAR CUBS
Polar bear baby cubs usually born in December or in early January in their den. Usually they born in pairs; though it is seen that there are three cubs or one cub, but it is almost rare that there are four cubs. A traditional area of these dens is called Bogan Valley. These dens are find just below the Ridge of Retzuis mountain, which is in Svalbard.
We know that polar bears are the one of the largest and deadliest carnivore of the bear family. But it is very funny that cubs of the polar bears are very much opposite. They are very much dependent and helpless. It is seen that male cubs are bigger than the female cubs.
INFORMATION ABOUT THOSE DENS-
When the ice floes break up in the fall, ending the possibility of hunting, each of the pregnant females digs a suitable dens. Each of these dens has one or two narrow entrance tunnel which leads their main chambers. Each den has one to three chambers. These dens usually are in the snowdrifts, but they may also be made underground in permafrost[1] if it is not sufficiently cold enough yet for snow. Normally these dens are situated on the land which is a few kilometers away from the seacoasts. Those who do not have den on the land, they have their den on the sea ice.
BIRTH OF THE CUBS-
Within the middle of November, the female polar bears entered their den and closed the entrance tunnel of the den. There she enters a dormant state similar to hibernation[2]. This hibernation-like state does not consist of continuous sleeping; but in this time the heart rate of the polar bear slows down from 46 to 27 beats per minute. the body temperature of the polar bears do not decrease in this time. In this meantime female polar bears give birth to their children.
LIFE AT THE DEN-
New-born baby cubs are of around 12 inches long and of the weight around 450-690 g. New-born cubs are born in the den with no sense. They are deaf for the first 24 hours, they are blind for the first one week. Their smelling and walking ability do not develop for several weeks. After two months they will have grown a thick and protective fur. Their teeth emerged and they have the ability to walk but not in the outside, only inside the den. This den is for protection and it also provides a means of conservation of mother's heat. Mother polar bear never left their cubs alone in this time.
LIFE OUTSIDE THE DEN(EARLY STAGE)-
When the weight of the cubs are around 23-35 pound, which takes almost 90 days after birth, mother polar bear breaks open those entrance tunnel and get out of the den. Cubs also get out with the mother. Though it is too early for them to leave the den completely. The cubs and their mother used to roam near the den for almost two weeks after they came out of the den, sometimes it takes more than two weeks. In this meantime, the cubs used to be familiar with the world outside den and they also develop their walking muscle in this time. Though they are starting to wander outside the den, they remain in the den around 85% of the time during this early stage of life. In this stage of life they never sleep outside the den.
LIFE OUTSIDE THE DEN(LATER STAGE)-
When the cubs walking muscles are ready enough to walk in the snow without falling, mother polar bear first take them to the sea, and introduce them to the sea. If the sea is far from the den,or the family trapped into deep ice fall or open water, sometimes mother bear carry their cubs on their backs. Till the age of 18 months the cubs need intensive cares from their mother. After they crossed their age of 18 months, though they do not need intensive cares from their mother, they cannot live their life alone. Till the age of 30 months, they used to live with their mother. after that they started their new life, without their mother. After leaving the mother polar bear sibling use to live together for sometimes and hunt and share food. After some more time they used to live alone.
INFORMATION ABOUT THOSE DENS-
When the ice floes break up in the fall, ending the possibility of hunting, each of the pregnant females digs a suitable dens. Each of these dens has one or two narrow entrance tunnel which leads their main chambers. Each den has one to three chambers. These dens usually are in the snowdrifts, but they may also be made underground in permafrost[1] if it is not sufficiently cold enough yet for snow. Normally these dens are situated on the land which is a few kilometers away from the seacoasts. Those who do not have den on the land, they have their den on the sea ice.
BIRTH OF THE CUBS-
Within the middle of November, the female polar bears entered their den and closed the entrance tunnel of the den. There she enters a dormant state similar to hibernation[2]. This hibernation-like state does not consist of continuous sleeping; but in this time the heart rate of the polar bear slows down from 46 to 27 beats per minute. the body temperature of the polar bears do not decrease in this time. In this meantime female polar bears give birth to their children.
LIFE AT THE DEN-
New-born baby cubs are of around 12 inches long and of the weight around 450-690 g. New-born cubs are born in the den with no sense. They are deaf for the first 24 hours, they are blind for the first one week. Their smelling and walking ability do not develop for several weeks. After two months they will have grown a thick and protective fur. Their teeth emerged and they have the ability to walk but not in the outside, only inside the den. This den is for protection and it also provides a means of conservation of mother's heat. Mother polar bear never left their cubs alone in this time.
LIFE OUTSIDE THE DEN(EARLY STAGE)-
When the weight of the cubs are around 23-35 pound, which takes almost 90 days after birth, mother polar bear breaks open those entrance tunnel and get out of the den. Cubs also get out with the mother. Though it is too early for them to leave the den completely. The cubs and their mother used to roam near the den for almost two weeks after they came out of the den, sometimes it takes more than two weeks. In this meantime, the cubs used to be familiar with the world outside den and they also develop their walking muscle in this time. Though they are starting to wander outside the den, they remain in the den around 85% of the time during this early stage of life. In this stage of life they never sleep outside the den.
LIFE OUTSIDE THE DEN(LATER STAGE)-
When the cubs walking muscles are ready enough to walk in the snow without falling, mother polar bear first take them to the sea, and introduce them to the sea. If the sea is far from the den,or the family trapped into deep ice fall or open water, sometimes mother bear carry their cubs on their backs. Till the age of 18 months the cubs need intensive cares from their mother. After they crossed their age of 18 months, though they do not need intensive cares from their mother, they cannot live their life alone. Till the age of 30 months, they used to live with their mother. after that they started their new life, without their mother. After leaving the mother polar bear sibling use to live together for sometimes and hunt and share food. After some more time they used to live alone.
DIET-
In the early stage of life when the cubs live inside
the den they just drink mother's rich-fat milk; this milk has a taste of the
cord liver and the smell of the seal and fish. The milk of the polar bear is
richer than the milk of the whale and contains more protein than the milk of
the seal. When the polar bear cubs are starting to go to the sea coasts with their mother, they first introduced to the solid food. In this time the cubs' diet is mother's rich milk and seal blubbers. After the age of 15-18 months the cubs are gone completely carnivore.
HUNTING-
Before the age of eight months they are not able to learn hunting. After eight months when they are use to go outside with their mother, they use to learn the way of hunting. Generally they first learn to hunt seals. They develop their hunting skills by watching their mother, hunting seals. But they need a lot of time to perfectly execute this technique.
THREATS-
The only threat for an adult polar bear is the human. Human hunts polar bears for their body parts. We will discuss about this in my later posts. Though human is not the threats for the polar bear cubs, they have many other threats. Their first threat is starvation.Since they are completely dependent on their mother, So, before their birth, if mother polar bears cannot find enough food for them, then that winter becomes the last winter of the mother and the cubs. Their next threat is being hunted by other animals. In the beginning of the life, when they live their 85% time of life in the den, sometimes mother polar bears go outside the den for collecting food, in this time, some other carnivore take the cubs with them for their diet. And their final threat is the adult male polar bear. It is seen that male polar bears sometimes kill the cubs. Though I do not find any confirm information about this killing, but I think the males kills the cubs to be in a relation with the mother polar bears. As far the female polar bears are with their child they are not ready for breeding. So males kill the cubs to be in a relation with the female.
WORDS-
permafrost[1] = soil at or below the the freezing point of the water for two or more years
hibernation[2] = to pass the winter in a dormant state
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