In an extraordinary display of maternal instinct, scientists in Canada have confirmed a remarkably rare instance of a female polar bear adopting a cub that was not her own. This heartening event, described by experts as "curious behaviour," offers a fascinating glimpse into the complex social dynamics of the Arctic's apex predators.
A Surprising Discovery on the Ice
The story centres on a bear known to researchers as X33991. When scientists from Environment and Climate Change Canada and the non-profit Polar Bears International first fitted her with a GPS tracking collar in the spring, she was caring for a single cub. However, a routine observation last month revealed a stunning change: the bear was now accompanied by two cubs of roughly the same age.
"Female polar bears are really good moms and so they’re just primed for looking after and caring for their offspring," explained research scientist Evan Richardson. "We think if there’s a little cub that’s bawling on the coast and has lost its mother, these females just can’t help themselves but to take them on and look after them. It’s a really curious behaviour."
An Exceptionally Rare Event
This adoption is a significant scientific observation. The bears are part of the Western Hudson Bay polar bear subpopulation, one of the most closely studied groups in the world, with research spanning nearly 50 years. Astonishingly, out of 4,600 bears monitored over the decades, this event represents only the 13th documented case of adoption ever witnessed within this population.
"Polar bear adoptions are very rare and unusual and we don’t know why they happen," said Alysa McCall of Polar Bears International, who called the sight "amazing." The two cubs, believed to be 10 or 11 months old, appear healthy and are expected to remain with their adoptive mother for approximately another 1.5 years.
Survival in a Harsh Environment
GPS data confirms the trio is now out on the sea ice. The cubs will depend entirely on their mother to hunt seals, sharing her catches and learning vital survival skills from her. This mentorship is critical in an environment where half of all cubs born do not reach adulthood, facing the dual challenges of winter hunting and summer fasting.
While having a mother dramatically improves the adopted cub's chances, history shows the odds are still long. Of the 13 documented adoption cases over 45 years, only three adopted cubs are known to have survived. Researchers plan to conduct genetic testing on the new cub to determine if its biological mother is known to them and might still be alive, as past cases have sometimes involved a "switching of litters" rather than orphaning.
"We might never know what happened to the mother," McCall reflected. "When we confirmed this was an adoption, I had a lot of mixed feelings. But it’s just another reason why this species is so incredible... It gives you a lot of hope when you realise that maybe, polar bears are looking out for each other."
