A female bear usually gives birth to a litter of between one and three cubs, and rarely four or more cubs. Bear cubs are born hairless and tiny, with a weight of less than half a pound and the gestation period varies between species.
The gestation period varies between species. For example, it’s between 195 and 265 days in the polar bear whereas it’s only 215 days in the spectacled bear.
Mother bears, around October or November, search for the best hibernation spot, which is usually under some tree log or stump that she will hide with leaves, twigs, and grass.
She delivers the offspring there in January. By the time the mom and her cubs emerge into spring, the cubs will already weigh around five pounds. Young bears grow fast and actually gain around 80 pounds by the time they’re one year old.
Cubs stay with their moms for around 18 months or until the mother bear is ready to mate again. This article explores how different species of bears give birth to cubs.
How Many Cubs Do Black Bears Have?
Black bears give birth to between one and three cubs, sometimes even a litter of four or more, but this depends on numerous factors. The mating season of the black bears begins in the summer, but the embryos don’t develop until the bear goes into her den.
Black bears give birth to tiny and hairless bear cubs in the middle of the winter period, somewhere around January and early February. Black bears are known to be solitary animals, except when it’s mating season or a mother is caring for her cubs.
When they come out of the mother’s womb, cubs feed on milk from the mother’s teats.
The black bear cubs are born blind and quite small-they weigh less than half a pound at birth or one tenth as much as human babies weigh at birth. By the time it’s spring and the mother and the cubs are ready to emerge from the den, the cubs will already weigh around five pounds.
Black bear cubs actually grow pretty fast and by the time they’re one; they already weigh around 80 pounds at that period. They stay together with their mothers until 18 months or until the mom is ready to mate again.
Black Bears are solitary animals by nature. Female bears can have several mating partners throughout their lifespan.
Read More: Do Bears Mate for Life?
Bear Smart notes that the average starting age of breeding for female black bears is three and a half years. They usually give birth every other year.
The males reach sexual maturity at approximately the same age as the females. The biggest bears in the population are usually the most prolific breeders.
How Many Cubs Do Brown Bears Have?
Grizzly females give birth to one to four cubs, but usually, they’re two. They’re commonly twins or triplets and born in January or February. The mother cares for her cubs inside the den until spring arrives and they step out into the world together.
When a female brown bear is pregnant, the embryo doesn’t develop for several months and this is known as delayed implantation. This is a common characteristic of all bear species and some other carnivores like seals and weasels.
If the mother can’t gain sufficient weight in the summer and autumn, the body “informs” her that she can’t continue with the pregnancy and the embryo is reabsorbed.
This allows the bear to gain sufficient weight and go through with the pregnancy the next year.
The gestation starts once the female goes into hibernation and it lasts between 180 and 250 days.
According to the National Wildlife Federation, grizzly females care for their cubs at least for two more years: she protects and feeds them.
Once the cubs reach the age of two and a half years, they usually separate from their moms. Still, if there’s not enough food, they may stay together longer.
In most cases, the separation happens when the mother enters breeding conditions and begins to attract male bears, which may pose a threat to the cubs. Grizzlies become sexually mature at the age of five.
Read More: Grizzly Bears vs Black Bears (Similarities and differences explained)
How Many Cubs Do Polar Bears Have?
National Geographic notes that polar bears usually give birth to one to three cubs. They enter dens (built on snowdrifts and slopes) and hibernate from autumn throughout winter and give birth to their offspring around January or February.
The mother bear feeds the cubs with milk through her teats until it’s spring and they all come out of the den.
Read More: Are Bears Mammals?
Female polar bears usually reproduce every three years or less often. Most polar bear males start mating at around eight to ten years of age. The females begin reproducing between age four and age six.
The implantation after the mating doesn’t happen until October in polar bears and it depends on the nutritional conditions of the mother-to-be polar bear.
Namely, if she’s gained enough weight for the pregnancy to happen, she can survive without food for as long as eight months (fasting in the summer and fall and the winter denning). The polar bear cubs weigh less than two pounds and are hairless.
However, by the time they come out of the den with their mother, the cubs already weigh around 20 pounds.
Polar bear cubs may stop nursing at 18 months, but may not separate from their mothers just yet for up to 30 months in order to increase their chances of survival, as explained on Sea World.
Mother bears are known to be highly protective of their cubs and often risk their lives to defend their offspring.
This video shows a rare white black bear protecting her cubs from another black bear:
Read Also: Polar Bear vs Grizzly Bear
Gestation Periods of Bears by Species
Most bears have a gestation period of around 200 days, though the exact length varies considerably between species, and even between individual bears within the same species. For example, the Giant Panda has a gestation period that can range from 95 to 160 days.
Here is a table showing the gestation period for some common bears:
|Polar Bear (Ursus maritimus)||195-265 Days|
|Brown Bear (Ursus arctos)||180-270 Days|
|Black Bear(Ursus americanus)||220 Days|
|Spectacled Bear (Tremarctos ornatus)||215 Days|
|Giant Panda (Ailuropoda melanoleuca)||95 – 160 Days|
Generally speaking, most species of bears give birth to one to three cubs. The females give birth to their offspring during hibernation in January or February and care for the cubs in the den until it’s spring and they come out together.
Female bears don’t mate for life and are known to have several mating partners throughout their lifespan. Baby bears are born small, blind, and hairless, but quickly gain weight and can reach an impressive weight of 80 pounds by the time they’re one year old.
The gestation period varies between species; some bears like the polar carry the cubs in their womb for up to 265 days whereas this period is much shorter than the panda bear, i.e. between 95 and 160 days.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.