During a winter dream (or hibernations) at bears metabolism strongly decreases and all exchange processes are slowed down thanks to what they don't spend energy for a metabolism and the movement. However their metabolism isn't slowed down completely, as during hibernation of gophers or other rodents therefore at bears it is called winter dream.
They spend the saved-up fatty stocks which save during the nazhirovochny period, and leave strongly lost weight a winter dream in the spring: during the winter they lose up to 30% of body weight. Strongly the level of basal metabolism decreases, proteinaceous exchange decreases, all processes, including pulse and breath are slowed down. Bears, naturally, in the period of a winter dream don't eat, they have no urination, and only in the spring when they begin to leave a den, they have these processes gradually, are step by step started.
At the same time during a winter dream at bears growth of bones continues, wool grows. Bears survive in the winter without food because it is caused by their nature. In the period of a winter dream at them the physiology, and later, in the spring very strongly changes, they leave a den and long time recover — this period is called walking hibernation. At the first exits they almost don't eat, at them occurs otkhozhdeny traffic jams, that is all remains of vegetation which have accumulated in intestines which they ate to a dream.
Bears endure the winter period in a condition of hibernation because there is no vegetable food necessary for them in the winter. Their diet approximately for 80% consists of vegetable forages. Bears consume a little animal food including small mammals, occasionally hoofed, birds and their eggs, insects and drop. Unlike other subspecies, the main nazhirovochny forage of the Kamchatka brown bear is made by fishes of family of salmon.
Bears of months on 5–6 sleep and leave dens in the spring when the first grass appears. All leave dens at different times: at first adult males, then single females and young individuals, and the last — the lactating females with bear cubs (approximately in April-May). On Kamchatka some large males don't sleep in general because there fish spawns in the winter too all the year round therefore they are able to afford not to sleep, and to continue to be fed.
There is an important event in life of bears in the winter: bear cubs are born during a winter dream of mother who sleeps rather weak dream and right after childbirth begins to lactate and lick cubs. Usually they are born in January-February, is rare at the end of December.
When there is a hunting on a den and hunters kill a bear, quite often it is killed a female near whom find tiny newborn bear cubs weighing 300-400 grams. Hunters often take away them to themselves, somehow nurse, bring up human food, and then these orphan bear cubs often grow in huge impudent uncontrollable bears, and owners should kill them.