Is a Grizzly Bear a Brown Bear? Grizzly Names Explained

One species, many names

The brown bear lives across North America, Europe and Asia, and people in different places gave it different names long before scientists compared them. In Europe it is simply the brown bear, or the Eurasian brown bear (U. a. arctos). In North America, settlers and naturalists called the inland bears “grizzlies” and the huge coastal bears “brown bears”, and the island bears of Kodiak “Kodiak bears”.

Scientifically, all of these are populations of brown bear. They can interbreed freely, and genetic studies show that bears move and mix between neighboring populations. The names describe where a bear lives and how it looks, not a separate species.

Grizzly vs coastal brown bear in North America

The practical difference is location and food. A popular rule of thumb in Alaska is that brown bears living within about 160 km (100 mi) of the coast, with access to salmon, are called brown bears, while those living farther inland are grizzlies.

Coastal bears are bigger mainly because salmon is rich, fatty food that is easy to catch in summer. Interior grizzlies live on poorer food and a shorter growing season. If a young grizzly were raised on the coast, it would likely grow larger too.

Where does the Kodiak bear fit?

The Kodiak bear (U. a. middendorffi) lives only on the islands of the Kodiak Archipelago in southwestern Alaska. It has been cut off from mainland bears since the end of the last Ice Age, roughly 10,000–12,000 years ago, and genetic tests show it is the most distinct brown bear population in North America.

Kodiak bears are the largest brown bears, with big males weighing about 480–635 kg (1,050–1,400 lb) in autumn. About 3,500 live on the archipelago. Most people do not call them grizzlies, but they are still the same species.

How many subspecies of brown bear are there?

Brown bear classification has a messy history. In the 19th century, North American grizzlies alone were split into as many as 86 “species”, based mostly on skulls collected by hunters. Later reviews reduced these sharply, and today most authorities recognize somewhere between a handful and about 15 living subspecies worldwide.

In North America, two names are widely used: U. a. horribilis for grizzlies and most mainland brown bears, and U. a. middendorffi for Kodiak bears. Some older names, such as U. a. gyas for the Alaska Peninsula bears, are still seen, but genetic research suggests they are ecotypes, populations shaped by their environment, rather than true subspecies. The debate continues because genes, body size and geography do not always line up neatly.

Where does the word grizzly come from?

The explorers Meriwether Lewis and William Clark wrote of “grisley” bears in 1805. The name is usually explained by the grizzled coat: many guard hairs on a grizzly’s back and shoulders are brown at the base and silvery or cream at the tip. The scientific name horribilis, given in 1815, reflects how fearsome early settlers found these bears.

Grizzlies once lived as far south as Mexico and as far east as the Great Plains. The California grizzly, which still appears on the state flag, and the Mexican grizzly were wiped out by the 20th century. Today the contiguous United States has about 2,000 grizzlies, mostly around Yellowstone and in northwestern Montana.

Where grizzlies and brown bears live today

North America has roughly 55,000–60,000 brown bears. About 30,000 live in Alaska, where both coastal brown bears and inland grizzlies are common, and about 25,000 live in western Canada, mainly British Columbia, Alberta, Yukon and the Northwest Territories. Across the Bering Strait, the same species continues through Russia, which has the world’s largest brown bear population, and on into Europe.

How to tell a grizzly from other bears

Because color is unreliable, wildlife agencies teach shape instead. Grizzlies have a muscular shoulder hump, a dished face, short rounded ears and long, gently curved front claws. American black bears, which share much of the grizzly’s range, have no hump, a straight face profile and taller ears; see grizzly bear vs black bear. For size and weight details, read how big do grizzly bears get?

The polar bear is the brown bear’s closest relative. The two can produce hybrids, sometimes nicknamed “pizzly” or “grolar” bears, and several have been confirmed in the wild in the Canadian Arctic.