What's the Difference Between a Brown Bear and a Black Bear?

You'll never see a wild Ursus americanus, or black bear, outside North America. Even though it's the most populous bear species alive today, the black bear is restricted to Canada, Mexico, Alaska and the contiguous United States (sorry, Hawaii).

Brown bears, Ursus arctos, are less common in terms of sheer numbers. But they've got the widest geographic range of any modern ursid. Indigenous to both North America and Eurasia, wild brown bear populations are dispersed from Spain to central Canada. And one extinct subspecies lived in Africa as recently as the 1970s.

Ursus arctos has subspecies galore. If you've ever been to Yellowstone National Park, or followed Memphis basketball, you should be familiar with at least one of them: The iconic grizzly bear (Ursus arctos horribilus).

Grizzlies once roamed a huge chunk of the North American continent. Due to human activities, however, they've become restricted to Alaska and northwestern Canada, along with portions of Montana, Idaho, Wyoming and Washington State.

Another brown bear subspecies encountered in this hemisphere is Ursus arctos middendorffi, the Kodiak bear. Found exclusively on Alaska's Kodiak Archipelago, it's one of the biggest predators that now walks the Earth.

Just how large does the mighty Kodiak grow? Large enough to sometimes rival the polar bear in size.

Weights of 1,058 to 1,179 pounds (480 to 535 kilograms) are considered "normal" for male Kodiak bears. Grizzly males are slimmer, averaging between 297 and 859 pounds (135 and 390 kilograms).

In both cases, females — or "sows" — belong to a different size class. Your typical Kodiak sow is around 20 percent lighter and 30 percent smaller (dimension-wise) than a normal male. Grizzlies have a similar disparity; most females weigh just 209 to 451 pounds (95 to 205 kilograms).

Standing on all fours, a grown male brown bear can measure 5 feet (1.5 meters) tall at the shoulder. And when they rear up, the biggest individuals assume the towering height of 10 feet (3 meters).

Black bears can't compete with those dimensions.

Their maximum shoulder height is closer to 3 feet (0.9 meters) and they stand a mere 5 to 7 feet (1.5 to 2.1 meters) tall when fully reared. Male Ursus americanus usually tip the scales at 130 to 500 pounds (59 to 227 kilograms) — whereas sows weigh between 90 and 250 pounds (41 and 113 kilograms).

So by the standards of his species, Smokey is no heavyweight.

Thankfully, you don't need measuring tape or a Yogi Bear-sized bathroom scale to tell Ursus americanus and Ursus arctos apart.

Brown bear shoulders aren't just taller by comparison. They're also more prominent, giving the creatures a distinctive "hump" when viewed in profile. It's a feature Ursus americanus lacks.

The black bear has straighter, shorter claws that help it climb trees and tear up logs. Meanwhile, the brown bear's long and curvy claws make great digging tools.

They also leave some very different pawprints behind. Brown bear forepaws leave a wider gap between the toes and the pad that sits behind them. And overall, black bear "hand" prints look rounder.

Relative to its body size, Ursus americanus has longer ears. The facial differences don't stop there. If you were to (somehow) draw a line from each bear's nose to the space between its eyes, you'd find that Ursus arctos has a more concave face.

Of course, these things are best observed from a nice, safe distance.

Zoologists consider Ursus arctos to be the more aggressive species, but both animals can maim and kill human beings. While attacks are statistically rare, there's no reason to tempt fate by getting too close to a wild ursid. The U.S. National Parks Service has a must-read safety guide for anyone planning to explore the black or brown bears' natural habitats.

Whereas black bears climb trees throughout their lives, brown bears stop doing this when they grow up. The two species are crafty omnivores who'll eat a wide range of plant and animal matter. Sometimes this means competing for the same resources; British Columbian salmon are hunted by black and brown bears alike.

Ursus arctos is able to kill much larger game than its cousin can. And Ursus americanus isn't necessarily off the menu. Believe it or not, there have been reported instances of wild brown bears preying on black bears.

About 110,000 brown bears are presently at large, along with an estimated 800,000 black bears. The International Union for Conservation of Nature doesn't list either species as endangered or "threatened." Grizzlies nevertheless enjoy some federal protection under the U.S. Endangered Species Act as of this writing.