Breeding
After a 2-3 months of gestation, 1 to 3 tiny cubs are born mid-winter, typically while the mother is still in the den. Newborn cubs – weighing less than a pound at birth -- are blind, toothless and covered with very fine hair. When they emerge from the den in early or mid-May, they will weigh 10 to 15 pounds. Cubs stay with the mother bear for their first year, denning with the mother and littermates over the winter. By the time of their second spring, they will be self-reliant and will separate from their mother by the second autumn.
Despite popular misconceptions, mothers with cubs rarely attack humans. However, it is never a good idea to get between a mother and cubs. Mothers will often perform a bluff rush to scare potential threats while the cubs will climb trees or other tall objects. If cubs become separated from their mothers, they can become lost and fall victim to vehicle collisions or predators.
Feeding and Hibernation
Over 90% of a bear’s natural diet is grasses, berries, fruits, nuts and plants. The rest is primarily insects and scavenged carcasses. With a nose that’s 100 times more sensitive than ours, a bear can literally smell food five miles away.
Most Colorado bears are active from mid-March through early November. In the fall, bears enter a period of compulsive overeating (hyperphagia). They start feeding for 22 hours a day and need to gain 20,000 calories a day to survive hibernation. Bears will work hard to get the calories they need, and can easily damage property, vehicles and homes. Bears are very smart, and have great memories - once they find food near homes, campgrounds, vehicles, or communities, they’ll come back for more.
When food sources dwindle they head for winter dens. A bear's hibernation period is also known as torpor, denning or winter lethargy. Unlike a true hibernator, bears can be stimulated to wake anytime during these inactive months.
Signs of Aggression
- Huffing
- Popping jaw
- Stomps a paw
- If your presence causes the bear to look up or change its behavior in any way, you are too close.
What do you do if you encounter a bear?
Black bears are highly intelligent and respond uniquely to people and situations. Black bears seldom attack unless they feel threatened, cornered, or are provoked.
If a bear comes near your home, do your best to safely chase it away. Yell, blow a whistle, clap your hands, and make other loud noises. But never approach a bear.
If a bear enters your home or yard, deterrents can be useful in areas where bears have already learned that where there are people, there is usually easy-to get-at food. The purpose of a deterrent is to make your home less attractive and persuade an exploring bear to move on. For a list of deterrents and more, see the "Dealing with an Intruder" section of the Keep Your Home Safer for Wildlife page.
A bear knowingly approaching a person could be a food-conditioned bear looking for a handout or, very rarely, an aggressive bear. Don't feed this type of bear: instead, stand your ground. Yell or throw small rocks in the direction of the bear. If the bear continues to approach, get out your bear spray and use it when the bear is about 40 feet away. If you’re attacked, don’t play dead. Fight back with anything available. People have successfully defended themselves with pen knives, trekking poles, and even bare hands.
Who Do You Call About an Aggressive Bear?
If you have an encounter with a black bear or an attack occurs, immediately contact Colorado Parks and Wildlife, Monday through Friday, 8am to 5pm. Before or after these hours, contact the Colorado State Patrol or your local Sheriff's department. If a person is injured by a coyote, call 911 immediately.
