Grizzly Bears: North America’s Furry Giants
Grizzly bears, otherwise known by their scientific name Ursus arctos horribilis, are a subspecies of the Brown Bear. Named after their ‘grizzled fur’, grizzly bears can live up to 25 years in the wild and range in colour from very light tan (almost white) to dark brown. With short, rounded ears and claws at least 2” long, their large shoulder backbone humps allow them to dig with massive strength. They are avid swimmers and can run up to 35KM per hour – quite impressive given their size!
In Canada, it’s estimated that roughly 20,000 grizzly bears remain in Western Alberta, the Yukon and Northwest Territories, and British Columbia.
Grizzly bears are solitary creatures but will warily tolerate company at concentrated food sources like a coastal salmon stream or a large patch of berries. During these times, they’ll use their posture, facial expression, sound, and smell (ex. droppings, urine, tree rubs) to communicate and relay information to each other, like their social status.
Did you know? Bear social status or ranking puts mature males on top, followed by females with offspring, single adult bears, and teenage bears at the bottom of the ladder.
A recent study has linked tree rubbing to increased attraction from the opposite sex. Scientists suspect that through rubbing or scratching their backs on trees, grizzly bears can relay information about their condition, how dominant they are, and information about their genetic makeup.
Although classified as carnivores, grizzly bears are omnivorous. Meat actually constitutes only about fifteen percent of their diet, with the rest being supplemented by a selection of plants at specific stages of growth throughout the year. Legume Hedysarum roots, glacier lily bulbs, and spring beauty are important food sources for grizzlies – specially in late March to mid-May, when bears leave their dens and food is scarce.
With only seven months to meet their nutritional needs, it’s no wonder that grizzlies have been reported to eat more than 200,000 buffalo berries in a single day! Other bear favourites include:
- Grasses and sedges
- Cow parsnip
- Horsetail (equisetum)
- Deer, elk or moose calves
- Carcasses of winter-killed ungulates
- Currant berries
- Blueberry/huckleberry (west of Great Divide)
- Whitebark pine nuts
- Ants, ant larvae, grubs
- Ground squirrels and marmots
- Deer, elk, bighorn sheep, mountain goats
- Carcasses of elk weakened or injured during the fall rut
(Source: Parks Canada, https://www.pc.gc.ca/en/pn-np/mtn/ours-bears/generaux-basics/grizzli-grizzly)
In the Central Rockies, berries are an important high-quality food source for bears. Due to this, grizzlies often concentrate their food scavenging efforts along dry forest edges and in the open forest, where berries are most likely to flourish. Burned forests are also key sites that support berry-producing shrubs and Hedysarum.
A Species of Special Concern
Today, prairie populations of the Grizzly Bear are considered locally extinct. Their presence was extinguished by human intolerance, market hunting, rapid conversion of their habitat into farmland, and exacerbated by the loss of important prey like buffalo.
Due to their sensitivity to human activities and natural events, grizzly bears are listed as a species of special concern by the Committee on the States of Endangered Wildlife in Canada (COSEWIC).
Habitat loss is the leading cause of Grizzly Bear population decline. Subscribe for updates to stay informed on our latest efforts to protect Canadian wilderness and support the creation of protected areas.