The tiny cubs are blind when born and look almost naked with only a covering of very fine hair. They will nurse as their hibernating mother sleeps, always remaining close to their mother to benefit from her warmth and the sustenance-providing nipples to which they are immediately drawn at birth. Prior to their entrance from the den, the cubs eyes will have opened and they will have experienced significant weight gains. They will also be covered with a thick covering of warm, insulating fur. The female invariably raises her young alone.
Bears are very protective mothers.
The female is very willing to fight in defense of her cubs. Adult males often present the greatest danger to young bears. Social Behaviour Previous beliefs whereby bears were seen living in isolation with the exception of the mating season has now given way to new understandings of the importance of the family unit as a basic construct of understanding bears and their behaviour. Young bears usually spend the first two to three years of life at the side of their mother and in the company of one or more siblings. With females coming into estrus, mating, conceiving and giving birth and then raising cubs in a repeating cycle, females live the majority of their lives within a family unit.