Brown Bear - Behavior

Behavior

The brown bear is primarily nocturnal. In the summer, it gains up to 180 kg (400 lb) of fat, on which it relies to make it through winter, when it becomes very lethargic. Although they are not full hibernators and can be woken easily, both sexes like to den in a protected spot, such as a cave, crevice, or hollow log, during the winter months. Brown bears are mostly solitary, although they may gather in large numbers at major food sources and form social hierarchies based on age and size. Adult male bears are particularly aggressive and are avoided by adolescent and subadult males. Female bears with cubs rival adult males in aggression, and are more intolerant of other bears than single females. Young adolescent males tend to be least aggressive, and have been observed in nonagonistic interactions with each other. Dominance between bears is asserted by making a frontal orientation, showing off canines, muzzle twisting and neck stretching to which a subordinate will respond with a lateral orientation, by turning away and dropping the head and by sitting or lying down. During combat, bears use their paws to strike their opponents in the chest or shoulders and bite the head or neck. In his Great Bear Almanac, Gary Brown lists 11 different sounds bears produce in 9 different contexts. Sounds expressing anger or aggravation include growls, roars, woofs, champs and smacks, while sounds expressing nervousness or pain include woofs, grunts and bawls. Sows will bleat or hum when communicating with their cubs.