In most regions births occur from November to February, while the mother is hibernating. The period of pregnancy is commonly extended 6-9 months by delayed implantation of the fertilized egg. Litter size is one to four young. The young are relatively tiny at birth, ranging from 225-680 grams each. They remain with the mother at least through their first autumn.
Bears are usually peaceful animals that try to avoid conflict.
However, if they consider themselves, their young, or their food supply threatened, they can become formidable adversaries. Only a small proportion of the stories of unprovoked attacks by bears on people are true. When such cases are carefully investigated, it is usually found that there was provocation. Nonetheless, bears have been persecuted almost throughout their range because of alleged danger to humans and because they are sometimes considered to be serious predators of domestic livestock. The Johns Hopkins University Press.