In northeastern Manitoba, scientists observing polar bears were surprised during a recent tracking mission. A polar bear mother and her cub, near Churchill in mid-November, were spotted with an additional cub that was confirmed not to be her biological offspring. This incident represents the 13th documented case of cub adoption within the western Hudson Bay subpopulation.
Alysa McCall, the director of conservation outreach and a staff scientist at Polar Bears International, expressed a mix of emotions upon confirming the adoption but mostly felt positive. She highlighted the remarkable nature of polar bears as a species, emphasizing their intriguing behavior and the hope it brings to see them looking out for one another.
Evan Richardson, a polar bear research scientist with Environment and Climate Change Canada, recounted an encounter with the mother bear and her single cub in Wapusk National Park in March. Later, during the fall, Richardson was astonished to witness the family of two bears expanding to include a third member – the newly adopted cub without a GPS tracking collar, unlike the other two.
According to Richardson, the rarity of such adoptions is evident in their long-term study, which has monitored over 4,600 individual bears and numerous litters over 45 years. The researchers estimate the mother bear to be around five years old, while both cubs are approximately 10-11 months old.
While the exact reason for the adoption remains uncertain, Richardson theorized that the strong maternal instincts of polar bears and their nurturing nature might have motivated the mother bear to take in the lone roaming cub.
Typically, polar bear cubs stay with their mothers for two to two-and-a-half years, during which they learn essential survival skills. McCall emphasized the importance of maternal care for cub survival, noting that the adopted cub now stands a better chance of reaching adulthood.
The fate of the adopted cub’s biological mother remains unknown, but Richardson hopes that genetic data collected from the cub will provide insights. Environment and Climate Change Canada collaborates with Polar Bears International and the University of Alberta to gather data on polar bears using GPS collars, aiding in monitoring their movements.
Adoption of polar bear cubs is a rare occurrence, underscoring the challenges faced by polar bears due to climate change. Richardson stressed the significance of female bears caring for additional cubs in the wild, highlighting the positive impact on bear populations in Churchill.
