Naturalist Notes

Distinguishing between the two types of bears in Greater Yellowstone can be tricky. But, by observing their physical features and behaviors, you can spot many differences. Let’s check out the distinct traits of grizzly and black bears.

Grizzly #399 taking a little rest from her 4 cubs at the time in Grand Teton National Park. Notice the shape of her claws, dished face, rounded ears, and prominent shoulder hump.

Traits of Grizzly Bears

• Large prominent hump above the shoulders
• Elongated, gently curved claws, similar to a shovel blade profile
• Short rounded ears
• A dished face, think of an orangutan
• Long “grizzled” guard hairs that are most pronounced around the girth band, and the facial margins.
• Generally larger size. females average 300-400 pounds and males around 400-550 pounds.
• Prone to hyper-aggression when acting in the defense of a food resource, offspring, or a perceived threat.

Grizzly bears are perfectly adapted for digging tasks. Their claw shape, resembling a shovel blade, is a deliberate feature enabling them to excavate efficiently. Paired with their strong, muscular-skeletal framework, these bears possess significant digging capabilities. These attributes prove invaluable when the bear needs to construct a den for hibernation, uncover carrion buried under thick winter snow, or access subterranean food sources. Despite their strength, grizzly bears can exhibit surprising delicacy in tasks demanding meticulous precision, like extracting insect larvae from tiny crevices using just a single claw.

In Hayden Valley, a grizzly sow with two cubs of the year in tow digs out a subterranean food source in rocky soil.

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The mentality of a grizzly bear is driven by a fierce urge to assert dominance over anything that obstructs its desires. Extreme aggression becomes prevalent when grizzlies perceive a threat to something they hold dear, whether it be a food source, family, or any other motivation. Particularly large male bears often exhibit behavior akin to that of a formidable schoolyard bully. They actively seek opportunities to pilfer fresh kills from wolves or intimidate rival bears into relinquishing their prey. Once the most imposing bear secures a carcass, its ownership remains unwavering, with little hope of deterring it. Typically, this dominant bear will guard the carcass fervently, indulging in an extended feast that epitomizes the concept of gluttony.

A large boar grizzly feeds on a bull bison carcass at LeHardy Rapids in Yellowstone National Park. Securing food resources of this quality requires hyper-aggressive behavior to establish and retain control. Notable are the lacerations on the bear’s face, evidence of a fierce altercation with another formidable boar vying for possession of the prized carcass.

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A black mother bear walks at the edge of the forest close to Yellowstone Lake. Look at her tall, pointed ears. See the straight line from her nose to her forehead. Notice her hips are even with her shoulders. This picture shows that color doesn’t always tell you the type of bear you’re looking at.

Traits of Black Bears

• More of a crescent shaped back, shoulders generally are lower or flush with the hips.
• Shorter claws with an abrupt hook, similar to a cat claw.
• Tall, pointy ears.
• Continuity from the head to the snout, contrasting to the dished face of a grizzly.
• Excellent tree climbers.
• Can be aggressive for the same reasons as a grizzly, but are less likely to do so.
• Females average around 150 – 200 pounds, and males around 250-350 pounds..

Black bear claws are relatively short, with an abrupt hook.
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Black bears are specifically suited for their forest habitat. Their distinctive claws, with a sharp curvature, are ideally crafted to navigate the wooded environment they call home. These specialized claws make it effortless for them to tear apart logs and access a diverse range of food sources. Moreover, these claws serve a dual purpose as they enable black bears to scale trees, seeking safety and nourishment within the rich offerings of the forest canopy.

A black bear demonstrating its superb climbing abilities.