Bears are one of natures most notorious hunters. They are big, fast and intelligent animals. They can out run some horses, and in human settlements, are known to take food from your bins. They might even try to enter your house. Cunning and intelligent, and always looking for a meal.
Baby bears however, give little away to tell you how big and dangerous they will become. As babies, they are small, cute, mischievous and curious. They are always up to something!
In this post, we explore some fascinating baby bear facts, and answer some of the most frequently asked questions about these amazing animals.
7 Fascinating Baby Bear Facts
Baby Bears Are Called Cubs
Similarly to some canids like baby wolves, or large felines like baby cheetahs and lions, a baby bear is called a ‘cub‘. They are born as a ‘litter‘, usually in a ‘den‘, though some are born in a ‘nest‘ – we’ll get to that later!
As they hit their first year, they move on from being cubs, to ‘yearlings‘, and after this they become ‘young adults‘, which they will remain until they reach sexual maturity.
Adult male bears are called ‘boars‘ and females are called ‘sows‘. Other than a litter of baby bears, there is no other collective noun to describe a group of young bears. In general though, a group of bears are collectively known as a ‘sleuth of bears‘ or a ‘sloth of bears‘.
Bears Are Usually Born With Siblings
It is not uncommon for a bear to give birth to multiple cubs in a litter. The average across the various species, is between 2 to 3 cubs in a litter, which they can have every 2 years. However, there can be between 1 – 6 cubs in a litter depending on environmental conditions and the species.
The availability of food has a part to play in the size of litter that a bear will produce, and they are usually born between the months of December to February, emerging from their den a few months later in spring.
Baby Bears Are Dependant On Their Mother
Baby bears are so small at first, with a very fine, light covering of fur. They are also hardly able to crawl, and are blind for around the first month after birth. They will remain in the comfort of the den for the first few months, nursing constantly from their mothers teats. There are 8 extant species of bear and all of them are dependant on their mothers at first.
Over the first winter, a nursing mother sow can lose up to a third of their bodyweight, which is why it’s so important they take on board enough fuel to survive a pregnancy. Non nursing mothers will lose only around half of that.
After the first winter, around 3 months later the baby cubs will have grown to between 4-6 lbs, depending on how many cubs are in the litter and how much milk the mother has been able to produce. Cubs in small litters with lots of milk tend to be larger than those from larger litters with less available milk.
Some species of bear don’t have to worry too much about winter, and some such as the Asiatic bear, don’t need to hibernate across much of their territory.
Mother Bears Can Pause Their Pregnancies
Some animals are able to pause their pregnancies through a process called “embryonic diapause” until conditions are right to have their offspring. Some examples include baby kangaroos, which are paused at the embryonic stage when they are around 100 cells big. Others examples include many rodents, seals and some deer.
While kangaroos pause their pregnancies until their pouch is empty and ready for a new arrival, bears pause for different reasons. The foetus will only start to develop when the mother has stored enough energy, body fat and nutrition to survive over the winter months while providing milk for her cubs. They won’t start eating again until the spring so it’s important they have enough fuel. If they don’t the foetus won’t grow.
So while they met may fall pregnant in June and gestate for around 7 months, the foetus won’t start to develop beyond the embryonic stage until around November when they have stored enough energy.
Some Baby Bears Are Born During Their Mothers Hibernation Period
It was once thought by some, that mother bears did not wake from their hibernation to give birth, but this is not the case. Studies show that when a mother is hibernating but starts going through later stages of pregnancy, their heart rate starts to increase. When they start the process of giving birth, their heart rate increases to normal ‘waking’ levels, returning to hibernation levels after the birth.
Research focusing on black bears also shows that despite their slowed down heart rates and breathing during hibernation, new mothers are alert to any threats and attentive to their new-born cubs needs.
Baby Bears Are Very Small
Baby bears can weigh less than a single 1lb at birth, potentially as small as 0.5 lb (8 ounces). Bears born in larger litters tend to be smaller than those in smaller litters. Larger litters tend to be slower to grow after birth too, as there is greater competition for the milk that the mother is able to provide.
For baby bears that are fed well, with lots of milk, by the time they leave their den at the start of their first spring, they are pretty nimble already, and will start to scale trees and play. Those fed less well are not so nimble at first.
While they may weight between 4-6 lbs by 2 to 3 months of age, they have a massive amount of growing to do to reach full size. With black bears for example, by the time cubs turn into yearlings, they can weight around 80 lbs, and double that a year later. It can take many years for them to reach their full size.
Some Baby Bears Live In Trees
While most species of bear live in dens above or burrowed into the ground, there is one species that does things a little differently.. The Asiatic black bear builds their nests up in the trees for birthing and raising their cubs. They also forage for a lot of their food in the trees, particularly fruits, nuts and nectar from bee hives. They are omnivorous though so will eat birds too, or their nests given the opportunity.
It’s strange to thing of an animal this size spending so much time off the ground, but these are one of the largest arboreal mammals. They spend up to half their time in the trees, and are great at climbing rocks too!
Baby Bear FAQs
What Is The Lifecycle Of A Baby Bear?
Bears usually breed in late spring to early summer, around June, though it varies. Polar bears for instance tend to mate earlier, anytime between January and June, though usually around March – April. The gestation period is usually around 7 months, but bears have the ability to pause a pregnancy if needs be.
Polar bears for example may gestate for between 7 to 9 months, and the foetus will only start growing when the mother is ready.
Once born, they will remain cubs for their first year, growing steadily until they reach their first year. Then as yearlings they still remain close to their mothers until they reach about 18 months of age. This will be their second spring and the mother will be preparing to have a new litter of baby cubs.
At this time, although they are still still effectively adolescents the mother will become intolerant and chase them away to fend for themselves. If the mother does not have a mate for that season, the yearlings may stick around for another year.
After two years old, bears become young adults but won’t reach sexual maturity until they reach about 3 to 4 years of age. It can take up to 8 to 10 years for a bear to reach it’s full size and weight. The brown bear as an example, can take up to 10 years.
The average life expectancy of a bear in the wild is around 18-30 years depending on the species, but they have been known to live longer – up to 35 years. Polar bears tend to live longer than black bears in the wild, as long as food availability is maintained.
How Big Do Baby Bears Grow?
Baby bears all grow to be very big, but how big is down to habitat, availability of food and also to the specific species.
The Kodiak Bear is the largest brown bear and can grow to weigh up to 1,500 pounds and 10 feet tall., but polar bears can be bigger. The sun bear on the other hand is the smallest bear and can weigh up to 150 pounds and grow up to 5 feet. You can read more about the bear sizes of all 8 species in our bear size comparison post.
What Do Baby Bears Eat?
For the first few months of their life, which in most cases is over their first winter, bears rely solely on thier mothers milk. A sow’s milk is full of fat and nutrients, but how much fat depends on the species. Polar bear milk is 33% fat, while Brown and Black bears milk contains around 20-25% fat respectively.
Most cubs start adding solid foods to their diet at a few months old, but they will continue nursing to some degree for as long as 18 months to 3 years if the mother skips a breeding season.
Once onto solid food, bears are omnivores and will eat a wide variety of food depending on their habitat and range. Their diet can vary widely.
Polar bears for example have a very limited diet in their range. They often have to rely on meat from other animals that roam the same territory. They often live near the coast for rich hunting grounds, and will eat different types of seal, narwhals (particularly baby narwhals which are easier targets), and walrus. Many of these prey are a big challenge for a young polar bear.
Where Do Baby Bears Live?
Most baby bears start their lives in dens, which are either underground or in trees, closely protected by their mother. Cubs stay with their mothers for about eighteen months, learning how to hunt and survive on their own. After leaving their mothers, young bears may stay together in packs, or they may disperse to find their own territory.
They live in a variety of habitats across North America, South America, Europe, and Asia, as well as in the Arctic Circle. There are many more bears in the northern hemisphere than in the southern hemisphere.
Panda bears as one example, have a very limited range in China, where they live in the wild. They rely greatly on bamboo as their source of food, which is not very nutrient rich. They have relied heavily on conservation and breeding programs to keep the species from going extinct.
What Are The Natural Predators Of Baby Bears?
Predators of baby bears differ by region. Those in the northern latitudes tend to have less predators, while those at lower latitudes have more predators to contend with until they come of age.
Tigers on the other hand are the main predator for the Asiatic bear, while black and brown bear babies have to watch out for cougars, coyotes, mountain lions and opportunistic wolves.