7 Astonishing Things You Didn’t Know About Grizzly Bears

We all know the grizzly bear basics. They’ve got fur for days, and impressive claws. They blissfully snooze away the snowy months, and are a total treat to see in the wild. But get ready to get your mind blown. Here are seven astounding things we bet you didn’t know about grizzly bears.

How Big Are Grizzly Bears Really?

Like humans, grizzlies vary in size. The average adult female will be around 300-400 pounds, while adult males are significantly larger and average around 700-800 pounds.

There’s some debate over the largest grizzly ever recorded, but there are reports of a grizzly in Alaska who is estimated to have been between 1200-1600 pounds and 10-12 feet tall! He could probably put away a few gallons of huckleberries!

Are Grizzly Bears Ever Small?

Yes! Newborn grizzlies are surprisingly small—about the size of a chipmunk—and they’re born over the winter while the mamas are hibernating. The cubs weigh about 1 pound when they’re born, and they nurse until mama wakes up in the spring. By that time they’ve eaten so much calorie-rich milk that they’re big and strong enough to walk out of the den!

You read that right: an 800-pound grizzly starts out the size of a chipmunk.

What Do Grizzly Bears Eat?

It’s a common misconception that grizzly bears are carnivores. They are classified as Carnivora, but they are mostly vegetarian! When it comes to nuts, seeds, and veggies it’s almost easier to list what a grizzly bear won’t eat.

Their spring and early-summer diet consists primarily of grass. It’s not all that exciting, but as summer progresses they spice it up with fruit. Grizzly bear’s favorite fruits are huckleberries and serviceberries, which they eat by the fistful. When preparing for hibernation grizzlies eat up to 30,000 berries in a day!

Another thing grizzlies eat by the tens of thousands are army cutworm moths and whitebark pine seeds.

In addition to the above, grizzlies eat a lot of worms, insects, roots, and tubers. They eat fish and rodents, and while they do eat large mammals, that’s not the bulk of their diet. Grizzlies are basically scavengers and they’re as likely to snack on carrion as they are to go after large prey.

Grizzlies have ambitious goals to eat about 90 pounds of food every day of the summer to prepare for hibernation. (Um… the ultimate pre-nap nosh-a-thon? Where do we sign up?)

How Many Grizzlies Are There?

It’s a mystery! Okay, kidding. Kind of. We don’t actually know. I mean, we have an idea, but grizzlies are notoriously hard to count. Ear-tagging and radio-collaring helps to estimate the numbers. Scientists use a data-analysis method known at Chao-2, but the Interagency Grizzly Bear Study Team (IGBST) says this estimating tool may be off by as much as 50%.

In the Lower-48 there are approximately 1,850 bears. Here’s the breakdown by ecosystem as of January 2020:

• Northern Continental Divide Ecosystem: > 1,000
• Greater Yellowstone Ecosystem: > 700
• Selkirk Ecosystem (including British Columbia): 80
• Cabinet/Yaak Ecosystem: 50
• North Cascades Ecosystem: < 20
• Bitterroot Ecosystem: 0?

How Fast?

No, I don’t mean how fast can a grizzly bear run—which is fast, by the way: about 35 mph, which is a solid 8 mph faster than Usain Bolt’s top speed—I mean how quickly do grizzlies reproduce. That answer? Not very fast at all.

First of all, females generally give birth to one or two cubs every three years. This is just one reason why 399’s birth of four cubs this spring was remarkable. 399 is also 24 years old, making her one of the oldest known grizzlies living outside captivity!

Female grizzlies reach reproductive maturity between ages 3 and 8, and typically bear 10 cubs over their lifetime, but not all will make it past the first couple of years. When a female grizzly dies, it takes 10 years to replace her in the ecosystem.

Fun Fact: Grizzlies aren’t monogamous and cubs in the same litter can have different fathers. (Scandalous!)

Where Do Grizzly Bears Live?

Everywhere! But not really, and not anymore.

Grizzlies once roamed most of Western North America, but their habitat has been reduced to about 2% of that area. Grizzlies have a large home range—500-600 square miles—which sounds like a lot, but it all happens with six recovery zones in Washington, Idaho, Montana and Wyoming.

Do Grizzlies Earn Their Keep?

Yes! Millions of people visit Yellowstone National Park every year specifically to see grizzlies, and “bear viewing alone contributes $10 million to the local economy of the GYE and supports over 150 local jobs.”

But it’s not all about money. Grizzlies play an important part in the overall health of the planet. As a keystone species, grizzlies help us keep it together, literally. If grizzlies disappear, there is no other species that can fill their role in the ecosystem.

We need the grizzlies, and the grizzlies need us to care.

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