The word “grizzly” in its name refers to “grizzled” or grey hairs in its fur, but when naturalist George Ord formally named the bear in 1815, he misunderstood the word as “grisly”.
The grizzly bear is a subspecies of the brown bear.
A pronounced muscular hump occurs on their shoulders which strengthens their front limbs for digging and running.
Grizzlies can attain a speed of about 35 mph.
Once mated with a male in the summer, the female delays embryo implantation until hibernation.
On average, females produce two cubs in a litter and the mother cares for the cubs for up to two years, during which the mother will not mate.
Although grizzlies are of the order Carnivora and have the digestive system of carnivores, they are actually omnivores, since their diet consists of both plants and animals.
In preparation for winter, bears can gain approximately 400 lb (180 kg), during a period of hyperphagia, before going into false hibernation.
The bear often waits for a substantial snowstorm before it enters its den: such behaviour lessens the chances that predators will find the den. The dens are typically at elevations above 6,000 feet (1,800 m) on north-facing slopes.
Once the young leave or are killed, females may not produce another litter for three or more years, depending on environmental conditions.