1. Birth: Brown bears give birth to cubs every two to three years, typically in the winter den. Litter sizes range from one to four cubs, with two or three being the most common. Cubs are born blind and helpless and weigh only about 1 pound (0.5 kg).
2. Nursing and Growth: The cubs stay with their mother in the den for several months, nursing and gaining strength. They begin to explore the outside world in the spring, but they remain dependent on their mother for food and protection for the first year or so.
3. Independence: By the time they are two years old, brown bear cubs are independent and will leave their mother to establish their own territories. Young bears may travel long distances in search of suitable habitat.
4. Mating: Brown bears reach sexual maturity at about five years of age. Mating occurs in the spring or early summer, and males compete aggressively for the opportunity to mate with females.
5. Dormancy (Hibernation): Brown bears are known for their long winter dormancy, which can last for up to seven months in some populations. During hibernation, bears enter a state of deep sleep and their body temperature, heart rate, and breathing slow down significantly. They typically hibernate in caves, under fallen trees, or in large nests made of vegetation.
6. Spring Emergence: Bears emerge from hibernation in the spring, when the weather warms up and food becomes available. They may lose up to 30% of their body weight during hibernation and need to eat a lot to replenish their energy reserves.
7. Feeding and Reproduction: Brown bears are opportunistic omnivores and their diet includes a wide variety of plant material (such as berries, fruits, and nuts) as well as animal prey (such as fish, small mammals, and ungulates). They are also skilled predators, capable of taking down large animals like moose and elk. Females give birth to cubs every two to three years.
8. Lifespan: Brown bears typically live for 20-25 years in the wild, although some individuals have been known to live for longer. The main causes of death for brown bears are hunting, habitat loss, and conflicts with humans.
It's important to note that the specific details of a brown bear's life cycle may vary depending on the subspecies and the geographic region in which it lives.