Different bears
Alberta is home to 2 bear species, the black bear (Ursus americanus) and the grizzly bear (Ursus arctos horribilis).
Image 1. The different features of the black and grizzly bears.
Bear physical features
Table 1. A comparison of the physical features of the black and grizzly bears.
| Black bear | Grizzly bear |
|---|
- In profile, the snout and face normally form a straight line.
| - In profile, the snout and face are normally dish-shaped.
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- Black bears have prominent ears.
| - Grizzly ears are small and round.
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- There is no hump between the shoulders.
| - There is a hump between the shoulders
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- The claws of the front feet are short and dark-coloured.
| - The claws of the front feet are long and light-coloured.
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- When black bear tracks are clear, they can be distinguished from a grizzly's track by the curved line made by the front toes. The black bear's claws leave little or no imprint in front of the toes.
| - When they are clear, grizzly tracks can be distinguished from a black bear by the comparatively straight line made by the toes. The claw imprints are easier to see, usually 2 to 3 inches in front of the toes.
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- In adult black bear tracks, the front print is 10 to 13 centimetres (4 to 5 inches) long and the back print is 15 to 23 centimetres (6 to 9 inches) long.
| - In grizzly tracks, the front print is 13 to 18 centimetres (5 to 7 inches) and the back print is 25 to 30 centimetres (10 to 12 inches) long.
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- Grizzly and black bears of similar size will leave similar sized tracks, but black bears are normally smaller than grizzlies and will leave smaller tracks.
| - The grizzly gets its name from its "grizzled" or silver-tipped fur. However, not all grizzlies have silver-tipped fur, and those that do might not have it at all times of the year.
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- When standing on even ground, a black bear's body is highest at the rump.
| - When standing on even ground, a grizzly's body is the highest at the shoulder hump.
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- Adults weigh from 45 to 200 kilograms (100 to 440 pounds).
| - Adults weigh from 100 to 400 kilograms (200 to 880 pounds).
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- Color varies from black to blond.
| - Color varies from black to blond.
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Reproduction
Table 2. A comparison of reproduction of the black and grizzly bears.
| Black bear | Grizzly bear |
|---|
- Black bears reproduce in greater numbers than grizzly bears and so can sustain higher rates of mortality.
| - Grizzlies do not have many cubs, so human-caused mortality such as poaching and vehicle collisions must be reduced to sustain a healthy grizzly population.
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- Female black bears
- Often have their first cubs at 4 years of age
- Give birth to 2, 3, or even 4 cubs at a time
- Have cubs every 2 years
| - Female grizzly bears
- May not have cubs until as late as 6 years of age
- Typically have only 1 or 2 cubs per litter, occasionally have 3 cubs
- Have litters only every 3 or 4 years
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Food sources
Table 3. A comparison of the food sources of the black and grizzly bears.
| Black bear | Grizzly bear |
|---|
- Black bears primarily eat plants, berries and insects, such as ants. Some individual black bears may learn to hunt ungulates, particularly fawns and calves.
| - Grizzly bears eat plants, berries and insects. Grizzlies are slightly more carnivorous than black bears and more commonly hunt large mammals as prey.
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- Black bears will eat carrion when they can find it.
| - Grizzly bears have large home ranges and travel long distances, which increases the chance that they will locate improperly stored human garbage, livestock feed or other unnatural food sources.
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- Black bears have an extremely strong sense of smell and can easily locate potential new food sources.
| - Grizzly bears have an extremely strong sense of smell and can easily locate potential food sources.
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- Their constant need to eat may overcome their natural fear of humans and human-use spaces, such as garbage, bird seed or pet food, especially if food or garbage is improperly stored.
| - Like black bears, grizzlies will overcome their natural reluctance to approach humans if carelessly stored food and garbage are available in human-use spaces.
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- Black bears must consume large amounts of food to prepare for winter denning. From mid to late summer, buffaloberries and other berries are an essential natural food source.
| - Like black bears, grizzlies use buffaloberries and other berries as an important source of calories to prepare for winter denning.
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Preferred habitat
Table 4. A comparison of the bear habitats.
| Black bear | Grizzly bear |
|---|
- Black bears evolved in forested habitats and have developed the curved claws that enable them to climb trees. They use this ability to climb trees to escape dangerous situations.
| - Grizzly bears evolved to survive in open habitats. This means their claws have developed for digging and not for climbing trees. However, younger grizzlies still have the curved claws that enable them to climb trees to avoid danger. Even older grizzly bears can climb trees that have large enough branches.
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- The black bear inhabits most of Alberta's forested land.
| - The grizzly bear prefers more open areas in the mountains, foothills and parts of northern Alberta. Grizzlies rely on younger forests and areas near streams and rivers to find their preferred foods.
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Self-defence
Table 5. A comparison of how the bears defend themselves.
| Black bear | Grizzly bear |
|---|
- Female black bears will typically send their cubs up trees when they feel threatened.
| - Because grizzlies evolved in areas with few trees, they learned to defend their young by acting aggressively.
- Confrontations for grizzlies are potentially risky. They attempt to avoid them by scaring away intruders with a display of their superior strength. They do this by bluff charging, jaw-popping and swatting the ground.
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- Because black bears use trees for escape, they are less likely than grizzly bears to aggressively defend their young or a prey carcass.
| - Grizzly bears are extremely possessive of prey carcasses and will aggressively defend them.
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