Where do baby polarbears come from?

After successful mating the mother-to-be bear will gestate for about 8months. Of these 8 months the emryo will only actually develop for about 4 months. During the other 4 months the egg may just be hanging out in the uterus doing nothing other than waiting for the appropriate time of year, or for good conditions and for the mother to get fit and prepare herself for the pregnancy & birth.

So as to ensure successful pregnancy the female will deposit fat and gain about 200kg. Come October (or early August) she will seek a den. Usually dug in snow drifts on southerly facing slopes & mostly on land within 16km from the coast - although this can vary wildly. Whilst pregnant she doesn't hibernate but will sleep soundly, although she is easily roused. Her heart rate drops from 46 beats per minute to about 27bpm. Her temperature doesn't drop much - if it does only by a degree or two - the pregnancy needs a higher body temp. She can give birth during this semi hibernation state.

The cubs are usually born November through to January in the Den. Usually two cubs will be born but sometimes it can be just one. On less common occasions three might be born and on very rare occasions she might actually give birth to four. The mother and her cubs will emerge from the den in late March to April. Usually females give birth once every three years. Sometimes it will be once every two years.

When a cub is born it is small and helpless with its eyes closed. It will weigh 454 to 680grams and be about 30cm long. Males will be born slightly larger than females. The fur is very fine which makes them look hairless.

During their first few weeks on Earth the cubs will spend the majority of their time drinking lots of milk courtesy of their mother. While nursing she will be sitting or lying down on her side or back. Over the next three or four months they will nurse as much as six times a day. The amount of times will gradually decrease as they get older. This milk is important for quick growth as the milkfat content is at about 33%. The cubs will stay with their mum for as long as 30 months, sometimes they will nurse for all this time but most cubs will stop after 18 months of age.

The cubs eyes will open within the first month. After about two months they will begin walking but won't leave the den yet. By now their fur has gotten whitish and their teeth have started growing.
By the time they emerge from the den in late March or April the cubs weigh about 10 to 15kg. When they first emerge from the den they will still stay near it for about 12 more days which gives time for the cubs to acclimatize to the colder temperatures and to develop their walking muscles. During this time about 85% of their time will still be spent in the den & they will sleep there at night.

After a time mum will then slowly, gradually with many rest stops, lead the cubs to the sea ice. Sometimes she will carry them on her back to cross deep snow or water. The mother is extremely protective and may even risk her own life to defend her new family.

The fat-rich diet of seals means the cubs grow quickly, by 8 months of age they weigh over 45kg.

My watching the mother hunt the cubs begin learning the valuable hunting skills that will help them survive for the rest of their lives. They will usually try to hunt during their first year but won't likely be successful until they are over 1 year old. Even then however they will only spend about 4% of their time hunting. At age two years they will be spending about 7% of their time hunting and should be able to catch a seal every 5 or 6 days.

Often during this period (spring) the mother will use the 'stalking birth lairs' method of hunting seals. This is when the mother finds a seal lair in which there is a pregant mother seal or mother seal with seal pups in it. The bear will rear up on hind leags and crash down on the lair with its front paws, bringing it down on the seal/s. This may take several attempts, during which the seal may escape. This method of hunting is especially useful at this time due to the extra high fat content of seal pups and mother seals, thus aiding most in mother and baby bear nutrition and growth. Additionally they are usually on ice attached to land and therefore the young bear cubs do not need to risk crossing water to eat (Male bears will not usually use this form of hunting, they have however been known to eat polar bear cubs).

The baby bears will often play together during childhood - chasing and tackling each other.

While adult bears usually make hissing, growling, champing of teeth and soft chuffing sounds when agitated or threatened, cubs make sounds more often and for more diverse reasons. They will also make whimpering sounds, lip smacking, squalling throaty rumblings. A mother bear will also warn cubs with a chuffing or braying sound.

The Polarbear mother is attentive to cubs, often touching & grooming them. They will comfort, protect or punish cubs by using body muzzle or paws.

TIME TO MOVE ON

At about 30 months of age the mother bear is ready to mate again. At this time either the mother bear or a male following her will chase away the cubs. From now on they are on their own. And the cycle will begin agian.

Breeding pairs usually stay together for a week or more mating several times. This should ensure that the female becomes again pregnant ready to bring forth the next bear generation.

Often male polar bears play fight, but during the breeding season (or in attempts to steal food) these fights can become real.

Male bears will initiate playfighting by approaching with head down, mouth closed and eyes averted, then make contact by gently touching or mouthing each other around face & neck. Then rear up on their hind legs and try to push each other over with forepaws.


Where do polar bears live, & where do polar bears go?
What Physical Features makes a Bear Polar ?
How do Polarbears get around ?
What & how do polarbears eat?
What do Polarbears do with their time?
Where do baby polarbears come from?
When and how do Polarbears die? - Dealings with Humanity*Still under construction*