The largest bear in the world and the Arctic’s top predator, polar bears demonstrate remarkable strength and resilience in the face of adversity. This has helped them earn the moniker Lords of the Arctic. At least two-thirds of the world’s polar bears live on Canadian territory. The polar bear’s Latin name, Ursus maritimus, means “sea bear.” It is a fitting name for this majestic species, which spends much of its life in, around, or on the ocean.
If you’ve ever wondered what the life cycle of these magnificent white bears is like, read on!
Mating
Unlike many other members of the animal kingdom, it is not ovulation that triggers mating, but rather the brief courtship ritual initiated by a male polar bear that triggers ovulation. It’s thought that females have scent glands on their feet that capture a male’s attention.
A male polar bear has roughly a one-in-three chance of mating with a female polar bear. His suitability as a mate depends on whether he is bigger and stronger than the other male bears that are scoping her out. Polar bears will spar and fight until one comes out on top, earning the right to mate.
Throughout the fall months, while polar bears are biding their time on land, males practice their sparring skills in anticipation of mating season, which occurs out on the sea ice in late spring. We often see them sparring in the fall during our Great Ice Bear Adventure and Polar Bear Photo Safaris in October and November.
Sparring practice at Dymond Lake Ecolodge. Zuopeng Wang photo.
Pregnancy and Gestation
After mating — often multiple times — the fertilized egg enters a state of dormancy known as embryonic diapause, or delayed implantation. For the embryo to become viable, a female polar bear must acquire enough fat during the feeding season to maintain the pregnancy once she enters her den.
If this condition is met, she will seek out a suitable denning area in mid to late fall and stay there until her cub(s) are born. Some polar bears dig dens in snowbanks on the sea ice, but denning on land in the peat banks of rivers and creeks provides better insulation.
Polar bears will carry one to three cubs per pregnancy, with two-thirds of pregnancies resulting in twins.
Birth and Early Years
Cubs are typically born in December and will stay in the den with their mom until March or early April. They weigh roughly one pound when born but grow quickly thanks to mom’s milk, which is 30% fat.
All the waterways surrounding Nanuk Polar Bear Lodge on the southern shore of Hudson Bay provide ideal conditions for denning. During our Den Emergence Quest, we monitor dens in anticipation of seeing moms emerge with their newborn cubs!
After exiting the den, the new family will begin a steady trek towards the sea ice, where mom will spend a couple of months hunting seals before returning to land. She needs to replenish her fat stores, which have depleted over the eight months she’s been on land, to keep feeding her young.
Cubs will stay with their mom for two to three years, learning how to navigate and survive in the Arctic before heading out on their own. Female polar bears will reach sexual maturity between four to six years of age, while males take a bit longer, reaching this stage between six and 10 years of age.
Waiting for the ice to form. Seal River Heritage Lodge. Boomer Jerritt photo.
Life Expectancy
Polar bears can live as long as 30 years, though most don’t make it past 25. The oldest captive bear on record was named Debby, and she lived to the age of 42. As female polar bears age, the number of cubs she has — and their survival rates — increases until she’s about 15. After that, her fertility starts declining.
Polar bears are at the top of the food chain; their only predators are humans, and sometimes, other polar bears. Hunting polar bears is not allowed in Manitoba, where our ecolodges are located, so the bears we see are curious, rather than fearful, of humans.
We’re able to walk with them and live among them for five months of the year because we’re exceedingly mindful of how we conduct ourselves. We maintain a distance that doesn’t make them feel threatened, we approach slowly and quietly, and we leave their environment as pristine as we found it.
Interested in seeing experiencing the Canadian Arctic with Churchill Wild? Get in touch!
Thank you all for being such good keepers and respecters of wildlife in the Arctic !
I visited Churchill in 2012 and 2018, both times with Barbara Stone, the polar bear artist, who arranged tours for us to experience Churchill and the experiences of nature including Polar Bear Viewing.
2012 trip: Barbara arranged a dinner at the Lazy Bear for the group. I was so blessed to dine with Doug and Helen Webber at my end of the table. I learned a lot about your lodges. The next day, there was a delivery of equipment scheduled to Seal River Heritage Lodge. Several of us ‘tourists’ climbed aboard the aircraft for the flight to Seal River Heritage Lodge. (I actually got to sit in the co-pilot’s seat). For me this was a dream come true.
WOW. The Lodge is spectacular and so in-tune with the environment. The experience will be forever in my memory bank.
God bless you all and may you always be successful, safe, and polar bear friendly.
Sincerely, Lonnie Stevenson
Keep on sending you newsletter to me. I love them all