GRIZZLY BEAR EVOLUTION

The evolution process of the Grizzly Bear is still relatively unknown. They are believed to have traveled to North America approximately 50,000 years ago.  They are subspecies of the Brown Bear and it is believed that due to environmental changes the Grizzly Bear ended up in the higher parts of North America. In order to survive, it had to develop a different type of coat as well as the hump on the back to help it have the strength necessary for survival.

BASIC CHARACTERISTICS OF GRIZZLY BEAR

Grizzly bears are among the largest land carnivores in the world. The heaviest recorded grizzly was 1496 pounds (Brown, 1993).Grizzlies grow to an average size of 6-7 feet when standing up and 3-4 feet to the top of their shoulders when on all fours. Grizzlies are avid swimmers and very fast runners, reaching speeds of up to 56km/h (35mph) in a sprint. Like most other bears, grizzlies have short, stubby tails.

Fur

• The fur of a grizzly bear can be anywhere from a cream color to a nearly black, dark brown coat (Brown, 1993)
• Cubs usually have a lighter coat
• The tips of their fur are white or silver which gives them a grizzled look, and led to their name, the grizzly bear
• Their pelt is highly insulating and protects bears from insects and the environment
• Their color helps grizzly bears blend in with their surroundings to avoid enemies and remain unknown to prey

Teeth

• Grizzly bears have 42 teeth (Brown, 1993)
• Several longer, sharp teeth are located towards the front of their mouth for tearing meat
• As they are omnivores, they have large, flat molars used for grinding
• Cubs begin losing their juvenile teeth at 5-6 months of age and have a full set of adult teeth at 1.5 years old.

Head

• Large head in relation to body size↔
• Skull length ranges from 30-40 cm
• Cubs have nearly round heads, which lengthen and change shape as they reach sexual maturity to assume the adult structure.
• Adults have a forehead with a steep slope leading into a long muzzle, giving them a concave or dish-shaped skull (Brown, 1993)
• Very wide nasal opening

Lifespan

• Grizzlies in the wild live to an average of 25 years, which is close to the life expectancy of most other bear species
• The oldest grizzly found in the wild was an Alaskan bear of 35 years

Sensory Function

• Excellent sense of smell is their main tool for detecting and locating food as well as evading conflict
• Short, round ears provide good hearing which is helpful in locating prey (French and French, 1989)
• Their eyes are forward, tiny and closely spaced
• Eyesight is generally thought to be poor and comparable to that of humans