The Difference Between Grizzly, Brown, and Kodiak Bears

The Difference Between Grizzly, Brown, and Kodiak Bears

Many people who come to visit Kodiak Island, Katmai National Park and other parts of Alaska for bear viewing opportunities often get a little confused about the differences between the various species and subspecies of bears. I often hear folks refer to Kodiak brown bears, as well as the coastal brown bears of the mainland of Alaska, as “grizzly bears.” However, technically, they are somewhat different.

Grizzly bears, coastal brown bears, and Kodiak bears are all the same species (Ursus arctos) (title on pic) but the grizzly bear (Ursus arctos horribilis) and the Kodiak bear (Ursus acrtos middendorffi) are considered separate subspecies, of which there are significant differences. In North America, brown bears are generally considered to be those of the species that have access to coastal food sources, while grizzly bears are essentially brown bears that live further inland and typically don’t have access to marine-derived food. The Kodiak bear is a coastal brown bear, which lives on the Kodiak Island archipelago, and has been isolated for twelve thousands of years from brown bears of the mainland of Alaska. They have a large bone structure and hold the unique title of being the biggest bear in the world, with the largest one on record being close to 1700 lbs. The polar bear does get bigger than the Kodiak bear, however, polar bears are classified as marine mammals.

The Difference Between Grizzly, Brown, and Kodiak Bears
While the polar bear does technically get bigger than the Kodiak brown bear, they are considered a marine mammal.

While both grizzly and coastal brown bears (including the Kodiak bear) are often referred to as carnivores, they are actually omnivores and eat a wide variety of foods. Grizzly bears eat berries, roots, plants, ground-dwelling rodents, worms, pine nuts, whatever carrion they can find, as well as moose, elk, deer, black bear, sheep, mountain goats, and other mammals that may live in their particular region…especially the calves of those animals.

Kodiak bears and the coastal brown bears of the mainland eat many similar things as the interior grizzlies, such as grass and other plants, berries, and dead animals, but a substantial portion of their diet consists of salmon and other coastal food sources, which greatly contributes to their enormous size. Coastal brown bears generally don’t expend the time or energy necessary to aggressively chase down and kill other mammals, since nutritious food sources are usually readily available and much easier to attain.

Besides differences in habitat and diet, there are also physical and temperamental differences between coastal brown bears and grizzly bears. Large male coastal brown bears can routinely weigh well over a 1000 pounds in the fall when gorging themselves on fish. In contrast, grizzly bears who live in interior regions of wilderness, weigh far less on average. Also, since the grizzly bear has much more limited food resources, and must work significantly harder at attaining them, they can be much more aggressive than the larger coastal brown bears.

The Difference Between Grizzly, Brown, and Kodiak Bears
The interior grizzly bear is generally more aggressive than the coastal brown bear de to having to work much harder to attain more limited food sources.

Both coastal brown bears and grizzly bears can vary in color, from shades of light brown and blonde, to dark brown and almost black in coloration. However, the fur of grizzly bears is typically lighter colored at the tips, giving them a grizzled effect.

The "grizzled" fur of the grizzly bear.
The “grizzled” fur of the grizzly bear.

While there are other differences between the various subspecies of brown bears, those are the main ones. So, I hope this article clarifies things for you a bit more.

(Scientific references: Alaska Dept of Fish and Game)

The Adventures of King Kodiak, The Biggest Brown Bear in the World, Joseph Classen
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To see more photos and video footage of the different bears, check out the video version of this story by clicking here.