White fur occurs in only one of every 40 to 100 black bears on the British Columbia mainland coast, but the trait is especially pronounced on certain islands in the Great Bear Rainforest.

Ideally, the hunting of black bears in the Great Bear Rainforest will become illegal, as the preservation of the recessive allele for white fur is crucial in maintaining the spirit bear population.

The trait is recessive: Both parents must carry a copy of the mutated gene for their offspring to be white. In the Great Bear Rainforest, some 500 to 1,200 black bears might be carriers.