Photo by: Patrick Connolly
Species: Black bear
Scientific name: Ursus americanus
Description: This is a large solitary carnivour. Being a bear, it has the typical features like a long snout (which is usually a lighter brown), long curved claws, and short stubby tail. This bear, is covered in a long coat which appears black, but can range from black to honey brown. Black bears have short, yet powerful legs, wide feet and nice long claws (which are not contractible). They have a large head with small eyes and small round ears. In this species, males are larger than females.
Habitat: Black bears are forest dwellers. They need a forest habitat to survive. Their body shape and curved claws are well adapted to climbing trees and dig for food. These bears have adapted to human settlements, and are commonly found around dump sites, and can be considered a nuisance when they associate humans with food. Black bears are able to travel tremendous distances, and have been relocated (moved) by biologists over 200km and will make their way back to their original home range (area where they live). Black bears spend the winter in a den. These dens are found in a wide variety of places, and may include caves, hollows under a log, hollows under tree roots or even a depression in the ground which the bear will cover with leaves. Winter time is hibernation time for bears. This means that during the winter months they “sleep” until spring. During hibernation bears will not eat, drink, urinate, or defecate (pooh). Hibernation is not deep for bear; instead they go into torpor, which is a state of low physiological activity. In torpor, bears are groggy and act as if heavily drugged. However, bears can “wake-up” during the winter, and may leave their den on mild winter days.
Breeding: Mating season for black bears is early summer (June-July). This the only time you will see a family of bears, as they are considered a solitary (live alone) animal. Although breeding occurs in early summer, females will not give birth to the young until January or February, while the female is in the den. Black bear reproduction is pretty cool, in that the embryos (fertilized eggs) will not implant and begin to develop until the female (sow) enters her winter den in November (process called delayed implantation). A female will have 1-5 young, average closer to 2-3. The number of cubs a female can have will depend on her body condition before entering the den. Females will spend the fall months eating as much food as possible before she enters her den. The fatter a female is the greater number of young she can produce. After cubs are born, they remain with their eyes closed until they are ~6 weeks old, and once their eyes are open, their activity level increases. In the spring, cubs will leave the den with their mother to search for food and learn to be a bear. The sow and her cubs will remain together through the next winter. Black bear cubs will disperse in their 2nd year to set up their own home range. Black bear cubs have a high chance of survival, with 80% survival to independence when they are with their mothers. Female black bears will only mate in alternate years due to the time needed to rear young.
Diet: Black bears are omnivours and will eat almost anything. Seasonal differences do influence their preference in food. A great proportion, up to 90%, of their diet is from plant material, including leaves, buds, flowers, berries, fruits and roots. These types of food are a diet staple in late summer and fall. Black bears will also eat small mammals, invertebrates, fish, and even young large mammals (e.g., deer fawns). They will also eat carrion (dead animals) and human garbage.
Threats to species: Black bears are a top predator, meaning they don’t have natural predators once they reach maturity. Although they are affected by disease, they will rarely die of disease. The biggest threats to bears are people (same old story), including habitat fragmentation (breaking up where they live), collisions with cars, and human-deer conflicts. Hunting is a method used to control bear populations in Ontario, and is used to allow for bears numbers to remain stable, while still controlling bear populations so they do not get too high. When populations are high, there is increased risk of bear-human conflict. Bears are also illegally poached because their parts (e.g., gall bladders) are used in traditional medicine.
Threats to humans: Bears need to be treated with respect. These beautiful animals won’t be look at you as a food source, but under certain circumstances, may associate you with food. Normally, bears will stay clear of humans. But if you happen open a bear who seems to be a little too curious or aggressive, there are things that you can do to try and get them to go away (I will include a link to this elsewhere).
During hibernation, bears will lose 20-40% of their body weight
Unlike most other mammals, bear lips are not attached to the gums. This helps them get food in small areas, e.g., holes in trees.
Although large and clumsy looking, bears can move quickly. They have been recorded running as fast as 55 km/hour over a short distance.
Black bears can swim, climb trees and have an incredible sense of smell.
Hinterland Who’s Who: http://www.hww.ca/en/species/mammals/black-bear.html
Eder, Tamara, and Kennedy, Gregory. 2011. Mammals of Canada. Lorne Pine Publishing. Edmonton, Alberta.