Arizona Public Radio | Your Source for NPR News
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Earth Notes: Bears’ Noses

A young Kodiak brown bear sits in a river whjile eating a decayed salmon. Bears eat as much as they can in the fall before they den, including salmon that have already spawned or are very decayed.
Hupp Lisa
/
Alaska Region U.S. Fish & Wildlife Service
A young Kodiak brown bear sits in a river whjile eating a decayed salmon. Bears eat as much as they can in the fall before they den, including salmon that have already spawned or are very decayed.

Many would guess a dog has the strongest nose in the animal kingdom, but actually, bears are believed to have the most acute sense of smell. It's 100 times better than a dog's sense of smell and at least 2,000 times better than a human's.

Bears are blessed with very large noses that are filled with scroll-shaped bones. These structures are coated with nasal mucosa which are packed with scent receptors — way more than you find in humans.

Another adaptation that allows bears to have an amazing sense of smell is their supersized olfactory bulb, the part of their brains devoted to processing smells. It's five times the size of humans. These structures in their noses and brains grant bears their super olfactory powers.

Why have bears evolved such powerful noses?

They are large omnivores with big appetites. Their unrivaled sense of smell allows them to detect high-protein food sources over long distances, even if the food is buried.

Also, bears range over large areas and use their noses to locate potential mates miles away.

Finally, bears' sense of smell helps to protect them from danger during their winter sleep. It can alert them to an approaching predator or human hunter while other senses are shut down.

The remarkable strength of bears comes as no surprise, but it's the strength of their noses that makes them nature's olfactory champions.

This Earth Note was written by Steve Schwartz and produced by KNAU and the Sustainable Communities Program at Northern Arizona University.

Steve first came to Flagstaff in the late 1970s to study at Northern Arizona University, where he obtained a master’s degree in biology, and he feels fortunate to have been able to call Flagstaff home for over thirty years. Recently retired after a long career in healthcare administration, his retirement allows him to spend large amounts of time exploring the rich diversity of the Colorado Plateau. Steve considers himself a lifelong learner and he can often be found exploring with his two dogs, Quinn and Rosie, indulging his passions for biology and the natural world.
Related Content