An Unexpected Family: Scientists Spot Rare Polar Bear Adoption

Researchers in northern Canada have recorded a rare and unusual moment in the wild: a polar bear mother raising a cub that is not her own.

The discovery was made during the annual polar bear migration near Churchill, Manitoba, often called the “polar bear capital of the world.”

Scientists first encountered the female polar bear in spring as she emerged from her maternity den with a single cub, which was ear-tagged as part of long-running population monitoring efforts. Tagging allows researchers to track individual bears and confirm family relationships over time.

When the team encountered the same female weeks later, they noticed something unexpected: she was now accompanied by two cubs.

One still carried the original tag, but the second cub had no identifying markers. After reviewing tracking data and previous sightings, researchers confirmed that the second cub could not be hers biologically — indicating an adoption.

Polar bear adoption is considered extremely rare. According to researchers, only 13 confirmed cases have been documented in this population over the past 45 years.

The circumstances surrounding the adopted cub’s biological mother remain unknown. She may have died, been separated during migration, or abandoned the cub — outcomes that typically mean low survival chances for young bears.

Staying with an adult female dramatically improves a cub’s odds of survival, providing protection, warmth, and access to food during a critical stage of development. Scientists say the case highlights the strong maternal instincts of female polar bears, even in one of the harshest environments on Earth.