Black bears (Ursus americanus) are huge mammals that typically show a small and narrow head, strong limbs and tiny ears. Mammals are generally vertebrate animals that are characterized by hair on their skin and mammary glands for feeding their offspring. The fur color of these animals ranges from a light shade of brown to black. Adult female black bears are approximately 200 pounds by weight, while the males weigh twice as much. The limbs of these mammals show 5 toes and sharp claws that have adapted for omnivorous feeding, which involves consumption of both plants and animals.
Black bears are highly adept to climbing trees as well as running fast. These animals are found in several states in North America, as well as Canada. The black bears are often found in areas of high elevations, such as the mountainous area that are above 3,000 feet above sea level. The diet of black bears is typically composed of tiny insects such as ants, as well as plant parts such as nut crops, acorns and berries. The diversity of their food varies, mainly depending on the season. Hence, insects are often their staple food in the summer, while the plant crops are their common meal during the fall season.
There have been reports that these black bears have adapted to eating young deer fawns on occasions. Black bears are easily attracted by food, and this has posed as an alarm to people who visit the woods. These animals have learned to be accustomed to the presence of human beings, thus resulting in the random appearances of black bears during mealtime of forest visitors. Such appearances have been mainly caused by the bears’ sensing of the scent of food brought in by people. It is also often observed that bears usually scavenge through garbage for food leftovers of human beings.
The acquired food preferences of black bears have caused damage in real estate properties during their foraging events. Another cause for such foraging behavior is the low amount of their food resource in the wild. Black bears reproduce particularly during the months of June and July, when food resources are highly abundant. These mammals have been determined to be opportunistic, or take the most advantage of the existing food resources while they are still plentiful. Unfortunately, their digestive systems are simply constructed, resulting in difficulty in absorbing essential nutrients from tough plant tissues.
Hence, the black bears are best fed with soft plant tissues such as berries and other softly chewable plants matter. Black bears have adapted special reproductive features, such as the delayed implantation process among females. A fertilized egg is kept in the uterus of the adult female for several months without undergoing any further development into a fetus. The fertilized egg will only progress further in its development when a physiological signal is sent by the body of the female adult black bear.
To date, the exact mechanism for this signal is unknown, yet it has been determined that the prolonged storage of the fertilized egg in the uterus of the adult female black bear is advantageous because it regulates the timing and frequency of giving birth to cubs. Such control of birth results in cubs that are born at the right time. It also assures the cubs that there will be enough food resource when they are born, because the prolonged storage of the fertilized egg provides time for the adult female black bear to accumulate enough food resources, as well as fat, which are needed during hibernation.
Should the amount of food resource be insufficient, the fetus is spontaneously aborted. Black bears hibernate by sleeping for three to four months at a specific body temperature of 88°F or higher. These mammals can optimally sleep for several months without losing any heat through the use of the stored fats in their bodies. The black bears also have the ability of controlling their bodies’ metabolic rate by half, so that they do not lose so much energy as they sleep for prolonged periods of time.
Generally, male black bears lose 30% of their weight during hibernation, while the female black bears lose 40%. These bears have the ability of keep their muscle form during the hibernation period. Black bears have the ability to regenerate their bones during hibernation. Black bears show specific behavior for communication with other black bears. The common parts of their body that are used for communication include the head, neck and mouth. An aggressive behavior is portrayed when a black bear walks with his head hanging lower than his shoulders.
Intimidation is shown when facial and mouth expressions are done, which include snarling, opening and closing the mouth, showing teeth, making noise with the mouth, and salivating. It is interesting to know that black bears may trick an intruder by approaching at a fast pace and stopping just right before the intruder. Such sight can definitely scare off the intruder, based on the speed of the black bear’s running, his size and his other facial expressions. Female black bear may bear offspring when they are of 4 years of age.
The females typically reproduce every 2 years, giving birth to an average of 2 to 4 cubs every time. The cubs are typically born during the start of the month of February, which is also the time when the female adult black bear is hibernating. The newborn cubs are light-weight, typically weighing less than a pound, and quickly gain weight upon nursing. Two to three months later, the cubs typically weigh around 5 to 7 pounds. The adult female black bear generally teaches the cubs where to forage for food until they grow to be independent enough to live on their own.