Canadian scientists have documented a rare case of a female polar bear adopting a cub, an event described as 'curious behaviour' that sheds light on the complex social lives of Arctic predators. The mother, known as bear X33991, was first fitted with a GPS collar in spring while caring for a single young cub. When researchers spotted her last month with two cubs of similar age, they realised they were witnessing an exceedingly rare adoption.
Evan Richardson, a research scientist with Environment and Climate Change Canada, said: 'Female polar bears are really good moms and so they're just primed for looking after and caring for their offspring. 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.'
The bears belong to the Western Hudson Bay subpopulation, one of the most studied in the world. Of 4,600 bears tracked over nearly 50 years, this is only the 13th adoption observed. Alysa McCall of Polar Bears International called it an 'amazing' sight, noting that adoptions are 'very rare and unusual'.
The two cubs, believed to be 10 or 11 months old, appear healthy and well-nourished. They are expected to stay with their mother for another 1.5 years, learning to hunt seals on the sea ice. However, survival is tough: half of all cubs do not reach adulthood, and of the 13 documented adoptions, only three cubs have survived.
Researchers plan to analyse genetic samples from the adopted cub to determine if its biological mother is still alive. In some previous cases, 'switching of litters' occurred rather than orphaning. McCall added: '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.'
