Male and female brown bears mate in late spring or early summer. Young, usually two or three cubs, are born in the mother's winter den between January and March. Usually, brown bears stay in their dens until April, May, or June. Young stay with the mother for one and a half to four and a half years. Brown bears live up to 30 years in the wild, and close to 50 years in zoos.
Brown bears wander widely for food, living solitary lives, except for mothers raising young.
However, in areas where food is concentrated, such as streams where salmon or trout are spawning, bears feed side by side. During cold months, from October or December through March or May depending on location and weather, brown bears sleep in dens inside caves, dug-out hollows, or dead trees. They emerge in warm weather. Brown bears rely upon scent more than hearing or sight to survey their surroundings. These wolves inhabit the same areas as brown bears in North America and parts of Eurasia.