Here's my notes on our two species of bears in North America, the Black bear and the Grizzly bear
:
Black Bear Facts:
Description:
*Scientific name: Ursus americanus, belongs to the Ursidae (Bear) family.
*Height: Range from 2-3 ? feet at shoulder height, range from 4-6 ? feet in length.
*Males weigh from 200-600 pounds, while females weigh 125-350 pounds.
*Black Bears are not always black in color-can be brown, light blonde, or cinnamon in color.
*Straight facial profile, oblong ears.
*Forefeet claws look like cat claws-short, pointed, and sharply curved.
*Cat-like claws enable them to be excellent tree climbers.
*A Black Bear track shows five toes but usually no claw marks.
Reproductive Biology:
*Breeding season runs from June to July.
*Promiscuous-pairings may last up to three weeks, mate several times daily.
*Gestation lasts 6-8 weeks, but embryonic development is delayed for up to 5-6 months.
*Cubs are born during January and February in dens where mother bears hibernate.
*Average 2 cubs, but litters can range from 1-5 cubs.
*Cubs are weaned at seven months, spend winter in the den with their mother, and then the family unit breaks up in the late spring season.
*Females breed in alternate years.
Habitat:
*Found allover U.S. except for desert climates.
*Primarily forest animals-abundant in mountains and forests of America, especially the West.
Diet:
*Black Bears are omnivorous, which means they eat both plant and animal foods.
*Diet is primarily plants, berries, small mammals and rodents, and insects. They love grubs for their high fat content!
*Occasionally attacks and kills smaller mammals, mostly young, elderly, or sickly animals.
*A favorite is the huckleberry!
*Like whitebark pine and pine nuts.
*Scavengers and opportunists-eat animal carcasses, raid trashcans for human food.
Interesting facts:
*Black Bears are both nocturnal and diurnal, meaning they are active at all hours of day or night.
*Single Black Bears with no cubs are usually solitary.
*Males may kill cubs, this is thought to be the bear’s population regulation practice.
*Reproductive rate is low but so is cub mortality rate-may be due to excellent maternal care.
*Black Bears don’t dig dens. Instead, they use natural rock or timbered shelters.
*Hibernation lasts from October or November through the following spring season.
*Black Bears are not true hibernators-they wake up during hibernation season but still spend most of the hibernation season in deep sleep.
*Climb trees when scared by humans or other perceived threats.
*Black Bears lose anywhere from 20 to 40 percent of their body weight during hibernation. Therefore, they must eat thousands of calories a day during late summer and fall.
Grizzly Bear Facts:
Description:
*Scientific name: Ursus arctos horribilis, belongs to the Ursidae family.
*Height: 3-4 feet at shoulders, 6-8 ? feet in length.
*Males weigh 500-1,000 pounds, and females weigh 225-550 pounds.
*Has a distinct shoulder hump.
*Dished-in facial profile, round ears.
*Grizzly bears vary in color-black, brown, straw-yellow, cinnamon. May have light-tipped guard hairs that give a grizzled or silvertip appearance.
*Claws on forefeet are long and gently curved-become whiter with age. Some of the claws are over two inches long.
*A Grizzly Bear track shows five toes, claw marks are generally seen in tracks.
Reproductive Biology:
*Breeding season runs from May through July.
*Males fight for females-promiscuous in nature.
*Gestation is 6-8 weeks, but embryonic development is delayed for 5-6 months.
*Cubs are born in den during January and February and leave the den in April or May with their mother.
*Average one to three cubs, a litter of four is unusual.
*Cubs are not weaned until they are yearlings in the following spring.
*Cubs den with their mother the winter after they are born.
*Reproductive rate: one cub per adult female every two years.
Habitat:
*Formerly dwelled on plains, prairies, mountains, and river bottoms.
*Currently, they inhabit remote wilderness areas, uplands, mountains, and the alpine tundra.
*Only resides in western North America. They can be most commonly found in Alaska, northwestern Canada, Washington, Idaho, Montana, and Wyoming.
Diet:
*Grizzly Bears are omnivorous-70 to 80 percent of diet is plants, berries, stems, flowers, and roots.
*Animal prey typically consists of small rodents, insects, and small mammals.
*Occasionally attacks and kills smaller mammals, mostly young, elderly, or sickly animals.
*Huckleberries are a favorite!
*Likes whitebark pine and pine nuts.
*Scavengers and opportunists-will seek out animal carcasses and raid trashcans for human food.
Interesting Facts:
*Grizzly bears were seen as equal to man before White settlers came in with their rifles.
*Grizzly bear cubs can survive as orphans due to their diverse diet. Having a diverse diet means less training time for them to learn how to find food.
Commonly known as a Brown bear or a Silvertip.
*Grizzly bears are mostly solitary but will congregate at food supplies.
*Grizzly bears dig out their dens for hibernation.
*They are not true hibernators-metabolism remains relatively high, body temperature drops very little, and they can be easily awakened from their deep sleep.
*Home ranges may overlap-Grizzlies are not territorial with each other when it comes to den locations.
*Their claws and heavy weight make them unable to climb trees, but they can reach up to twelve feet up a tree by standing on their hind legs. Grizzly cubs can climb trees.
Differences between Black Bears and Grizzly Bears:
*Grizzlies are larger in size than Black bears.
*Grizzlies may kill Black bears for territorial reasons.
*Grizzly bears are known to be the fiercest and most dangerous of all bears.
*Black Bears live in more locations within North America than Grizzly bears.
*Grizzly bears cannot climb trees as well as Black bears.
*Ears and facial profile, Grizzlies have distinct shoulder hump.
More facts about bears:
*Bears have become less fearful of humans due to humans feeding them scraps or not properly storing food or keeping a campsite clean.
*Bears become more aggressive when approaching humans for food, which ultimately leads to their euthanization.
*Contrary to myth, bear attacks are rare. More humans are killed by other humans, dogs, bees, and even lightning than bears.
*Bear attacks usually occur when humans come too close to cubs, or ignore the bear’s warning signs and continue to stay in place. The bear perceives this as a challenge.
