The Life of a Polar Bear Cub

Lead Scientist Cate Collins explores the transformation of polar bear cubs, from tiny newborns to independent sub-adults!

On our one-day polar bear expeditions, we’re sometimes lucky enough to spot moms with their cubs in the wild, a true highlight of the Arctic experience. This post explores the early life of polar bear cubs and the remarkable role their mothers play in helping them survive in the harsh Arctic environment.

Birth

Polar bears mate in April, but moms have a fascinating ability to delay implantation of the embryo until fall. This gives them time to fatten up before pregnancy officially begins.

While males return to the sea ice to hunt seals, females retreat into their dens. There, after a short two-month pregnancy, they give birth early in the new year.

Newborn cubs are blind, helpless, and weigh just over 1 lb. Their downy white fur helps keep them warm through those first critical months. Most litters have two cubs, while triplets are now increasingly rare.

Meet this cute and curious cub-of-the-year, spotted on our Ottawa Expedition at about 10 months old.

Early Stages

Cubs remain in the den with their mother for about three months, nourished by some of the richest milk in the animal kingdom, about 28% fat. This milk helps them grow astonishingly fast. By the time they leave the den, they’re nearly 20 times their birth size.

Once outside, cubs stick close to the den for a few weeks while they gain strength. Only then will mom lead them farther afield to resume hunting seals.

Polar bear mothers endure one of the longest fasting periods in the animal kingdom, up to eight months. They stop feeding when sea ice melts and forces them ashore in mid-July and won’t eat again until the following spring, once their cubs are strong enough to join them on hunts.

This mom and her cub had to make a quick retreat when a male showed up. Polar bear dads are not around to help, and sometimes they can be downright dangerous to the little ones.

Growing Up

Over the next two years, cubs learn everything from their mother, including how to hunt, swim, and survive the unforgiving Arctic environment. They continue to nurse, though the milk becomes less rich as their diet is gradually supplemented with seal meat.

Following mom everywhere, these playful cubs are busy learning the ropes before they set off on their own.

Transition to Independence

At around 2.5 years old, cubs become sub-adults as their mom leaves them to survive on their own. This stage lasts until they’re about five years old, when they’re considered adults and may start raising cubs of their own. Over a lifetime, a polar bear mother may have up to eight litters, usually one every three years, continuing into her late 20s.

Polar bear cubs experience one of the most remarkable transformations in the animal kingdom. To see them in the wild is to witness one of nature’s greatest survival stories. Join us on one of our one-day polar bear expeditions for the chance to experience this unforgettable sight firsthand.

References

McCall, A. (2025, February 1). Top mom and cub facts. Polar Bears International. Retrieved August 5, 2025, from https://polarbearsinternational.org/news-media/articles/polar-bear-mom-cub-facts/

Derocher, A. E., & Lynch, W. (2012). Polar bears: A complete guide to their biology and behavior. Johns Hopkins University Press.

About Gold Star Canadian Tours 

At Gold Star Canadian Tours, we focus on providing the worlds best travel experiences to authentically Canadian destinations. Our flagship tour is a convenient 1-day Polar Bear Expedition with dedicated non-stop charter flights from major airports directly to Churchill, Manitoba. With Gold Star Canadian Tours, the wonders of the Arctic are closer than ever. Your Adventure Awaits!