In a remarkable event observed by researchers in northern Canada, a polar bear mother has adopted a cub that was not biologically her own, a behavior documented only 13 times in 45 years of study. This rare adoption offers a glimmer of hope for polar bear conservation amid ongoing climate threats.
The adoption was captured on camera during the annual polar bear migration along the Western Hudson Bay near Churchill, Manitoba, a town renowned for its polar bear population. Scientists from Polar Bears International and Environment and Climate Change Canada were tracking the five-year-old mother bear, who was first seen emerging from her maternity den in March with one cub. By November, however, she was spotted with two cubs—the original tagged cub and an untagged newcomer, confirming the adoption.
This incident marks just the 13th known case of cub adoption out of over 4,600 polar bears studied in the western Hudson Bay area since 1980. Evan Richardson, a polar bear research scientist, noted that while adoptions are not unheard of, they are extremely rare, with only a handful observed despite hundreds of litters monitored over decades.
Researchers are uncertain why the mother adopted the lone cub, but they hypothesize that strong maternal instincts compelled her to care for the crying cub on the tundra. Alyssa McCall of Polar Bears International expressed mixed emotions, emphasizing the fascination and hope such behavior inspires. The biological mother of the adopted cub remains unknown, though genetic samples may provide clues.
The adoption significantly boosts the cub’s chances of survival. Polar bear cubs typically have a 50% probability of reaching adulthood when raised by a mother, but without maternal care, their odds are nearly zero. With climate change reducing sea ice and threatening polar bear habitats, every successful rearing increases the population’s resilience.
The adopted cub and its sibling, both around 10 to 11 months old, are healthy and will likely stay with their mother for about two and a half years. During this time, they will learn essential skills, such as hunting seals on the sea ice, crucial for their independence.
This event underscores the complex social behaviors of polar bears and highlights the importance of continued research and conservation efforts. As Richardson pointed out, ‘The bears need all the help they can get these days with climate change,’ making such adoptions a positive development for the species’ future in the Churchill region.
