Documentation of Polar Bear Adoption in Western Hudson Bay
Researchers in northern Canada have documented a rare instance of a wild polar bear mother adopting a cub not biologically her own. This event represents the 13th known case of adoption recorded among 4,600 bears studied over nearly five decades in the region.
Observations were made during the annual polar bear migration in Western Hudson Bay, near Churchill, Manitoba. A five-year-old female polar bear was initially observed with one cub upon emerging from her maternity den in the spring; this cub was subsequently tagged for research purposes.
During observations in the fall, the same mother bear was seen accompanied by two cubs: the previously tagged cub and an untagged cub. Scientists are currently attempting to identify the biological mother of the newly observed cub through genetic samples.
Alyssa McCall, a scientist with Polar Bears International, stated that the phenomenon of adoption is uncommon and its underlying causes are not fully understood. Evan Richardson, a polar bear scientist with Environment and Climate Change Canada, noted that successful fostering of additional cubs could benefit the polar bear population, particularly given challenges posed by climate change.
The survival rate for wild polar bear cubs into adulthood is approximately 50%. The presence of a nurturing mother is known to enhance a cub's chances of survival. Researchers have indicated that both cubs appear healthy and are expected to remain with their adoptive mother until they are approximately two-and-a-half years old. The family unit is anticipated to move onto sea ice, where the cubs will learn hunting skills for seals.