What are the Growth Stages of Polar Bear Cubs?

Courtney Nachlas July 7, 2019 0

There are few comparable thrills to spotting the world’s largest land predators only a few feet away from your Polar Rover. These impressive bears brave the Arctic’s unforgiving conditions and have a fierce presence as the infamous “kings of the arctic.” Yet, we can’t hide our joy and excitement when we spot these enormous bears as tiny cubs, playing near their mothers. How do these impressive creatures survive as helpless cubs? In order to appreciate their journey, we must understand the growth stages of polar bear cubs.

Photo Credit: Colby Brokvist

Newborns

Polar bear babies are typically born from November to January in a maternity den, which are cave-like holes dug into the snowbanks by the mother bear. Travelers on Nat Hab’s Ultimate Churchill Adventure will actually have the opportunity to helicopter to a polar bear denning area on their trip. These dens are oval shaped and provide a warm place to give birth to newborns. Polar bears, which are commonly born as twins, are around 12-14 inches long and only weigh a little more than a pound. When they’re born, polar bears are both blind and toothless, making them vulnerable to predators. These tiny polar bears are entirely reliant on their mother, who feeds them milk and keeps them warm during the Arctic winter. Quickly, the newborns grow into adorable cubs, but they will continue to nurse on their mother’s milk for approximately 20 months.

Den Life

During life in the maternity den, the polar bears will change and grow as the months go by. Within the first month, a polar bear cub will open its eyes. After two months, polar bears will learn to walk around their den. Their bodies have also begun to develop thick fur and their teeth are emerging by this time. Within only a few months, the polar bears will weigh between 20-30 pounds. To prepare for their journey to the sea ice, mothers will take their cubs outside occasionally to acclimate to the cold weather and to strengthen their muscles.

Photo Credit: Brad Josephs

Cubs

Once cubs are strong enough to make a journey to the sea ice, the mother will lead her cubs out of the den. This typically occurs in spring, only a few months after the cubs are born. Slowly making their way to the sea ice, the hungry mother will begin the seal hunt and continue to provide for her cubs. The cubs will quickly grow by feeding on their mother’s milk, which has an average 30 percent higher fat content than a human’s milk, and seal blubber. Lucky travelers will be able to witness this migration and observe the protective mothers teaching and guiding her cubs. The polar bear mother will use the time with her cubs to teach them how to hunt, swim and survive in their Arctic habitat.

Polar bear cubs with adult

A mother polar bear teaching her children to hunt for seals. Photo Credit: Mike Bruscia

Subadult

Generally, a polar bear cub will stay with its mother for two to three years learning valuable survival skills. Though they’re not usually great hunters in their first year, these cubs will quickly learn and begin catching seals. After the mother has raised her cubs to be able to survive in this harsh environment, they will be left to survive on their own. These polar bears are referred to as “subadults” from the time period between leaving their mother and becoming mature enough to mate. For females, mating will occur between four to six years of age while males will begin mating from six to ten years of age.

Without their mother, a polar bear cub would likely not survive. Photo Credit: Colin McNulty

Polar bears face many challenges in the early stages of life from being vulnerable newborns to slow cubs trailing their mothers. Yet, without their mother’s guidance, protection and support, they would most likely not survive. To truly appreciate the fiercest animals in the wild, we must also appreciate this difficult journey to maturity.

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