Bears, like all animals, depend on their senses to survive. They use their senses for many things, but especially to find food and detect possible threats. A bear’s sense of smell is its most important sense. A brown bear’s sense of smell is three to four times more sensitive than that of an average dog, and it is difficult for humans with our relatively poor sense of smell to comprehend what this means and how much a bear depends on this sense. A bear uses his nose to find food, locate a mate, and avoid danger. A bear downwind from you may smell your presence and run from you while you are still several hundred yards away from him.
A bear’s second most important sense is hearing. Brown bears have relatively small ears, but they can detect noises at a great distance. A bear can hear the click of a camera shutter over the sound of the wind, crashing waves, or a swiftly running river.
For a long time, biologists believed bears had poor eyesight, but scientific research has shown a bear’s eyesight is similar to that of a human’s. Bears are not nearsighted as was once believed, and they can see colors. Brown bears often stand on their hind legs to increase their sight distance and get a better look at an object. It is not a sign of aggression when a bear stands on its hind legs; the bear is just trying to gain more sensory input.
The important thing to remember is a bear does not use each one of these senses independent of the others. If a bear sees something unfamiliar in the distance, such as a person, a boat, or even another bear, he may stand on his hind legs to get a better look, raise his nose to attempt to smell the interloper, and pick up his ears to try to ascertain unfamiliar sounds. If he still cannot determine what the object is, he may approach it for a closer look or circle downwind from the object so that he can smell it better.
Next week, I’ll write about a bear’s fur and claws. Does a bear’s fur change with age? Why are some Kodiak bears blonde and others a chocolate-colored? What is the white ring some cubs have around their neck? How do the claws change with age?
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