The brown bear, a species belonging to the Ursidae family, possesses a body length ranging from 1 to 2.5 meters and weighs between 125 and 225 kilograms. Remarkably, some brown bears exceed 500 kilograms in weight, rendering them the largest terrestrial carnivores.
Due to their wide distribution across the globe, variations can be observed among brown bears in different regions. Their fur color also varies, ranging from light brown to dark brown, and even black, with some exhibiting white fur on their chests.
The brown bear exhibits remarkable adaptability, enabling its survival in diverse environments, from the fringes of deserts to alpine forests and even the Arctic ice fields. As a species with few natural predators, it enjoys a wide distribution in the Northern Hemisphere, spanning Europe, Asia, the Middle East, and North America (including Mexico).
The original distribution of brown bears in Europe serves as a testament to their ability to adapt to various environmental conditions.
Thriving not only in forests but also in grasslands and tundra, brown bears have inhabited vast territories with minimal or no human intervention. However, due to human interference and presence, many of the bear's former habitats have become unsuitable.
Inland brown bears occupy extensive territories, with males ranging across nearly 700-1000 square kilometers and grownup females occupying 100-450 square kilometers.
Conversely, brown bears residing near coastal islands have considerably smaller territories, with males covering only 133-219 square kilometers and females spanning 28-92 square kilometers. Overlapping territories are common among brown bears, with males occasionally sharing territories with multiple females.
Brown bears are solitary animals, although their territories often overlap with those of other individuals. They exhibit a strong sense of territory and employ various methods to mark their boundaries, such as scraping bark and leaving scent markings.
While brown bears do not actively seek out confrontations with other bears, they may display threatening behaviors such as standing up, growling, and slapping the ground when competing for territory or mates.
As omnivorous creatures, brown bears exhibit a wide range of dietary preferences. Their primary food source consists of plants, particularly berries, nuts, and roots. Additionally, brown bears prey on small mammals, fish, and insects. Their exceptional sense of smell and hearing enables them to locate food sources with ease.
Brown bears are nocturnal creatures, primarily active during the night. During the day, they seek out secure locations, such as burrows or dense bushes, to rest and avoid the heat. In winter, brown bears enter a state of hibernation, during which their heart rate and metabolism slow down to cope with harsh conditions and scarcity of food.
While numerous animals hibernate during winter, humans have not evolved this function. Among all Earth's creatures, brown bears exhibit the longest hibernation period, often sleeping until around April of the following year.
Brown bears hibernate not solely due to the cold weather, but primarily because of the scarcity of food during winter. Other small animals refrain from seeking food during this season, thus leaving brown bears with an unreliable food source.
Consequently, after millions of years of evolution, brown bears have gradually adopted hibernation as a survival strategy for winter. In contrast, polar bears do not hibernate during winter since they have abundant food sources in Antarctica.