It can be distinguished from the black bear Ursus americanus by its more concave face and a hump over the shoulders which the black bear lacks. Unlike the black bear, the brown bear cannot climb trees. They are more aggressive than the blacks. The Bajan Bear, U. a. californicus , became extinct in the 1920s. This North American species is usually black but often varies in colour.
Males are somewhat heavier than females.
They are essentially solitary creatures, males and females only coming together in June-July to breed. 2-3, but sometimes up to 5 cubs, are born after a pregnancy of about 220 days. Lifespan is about 32 years. Although those bears in isolated pockets may be endangered through reproductive isolation, generally this bear is not considered in danger. Yukon U. a. vancouveri Vancouver Island U. a. emmansii Blue Bear, Glacier Bear N British Columbia, Yukon U. a. cinnamomum Cinammon Bear SW Canada, W USA U. a.