Brown bears, commonly called grizzlies, have long evoked fascination. These intelligent mammals display dynamic behaviors that inspire onlookers with a myriad of questions. At some point, one may wonder which is the correct term for Ursus arctos—grizzly or brown bear?

Brown bear in Yellowstone.

The difference is regional: bears found inland are referred to as grizzlies, while those on the coasts are known as brown bears. Grizzlies are actually a subspecies of brown bear, Ursus arctos horribilis, found in dense forests, alpine meadows and mountain valleys. The principal distinctions of the grizzly are its physical appearance and diet. It takes its name from the ‘grizzled’ blonde-tipped fur that grows along its shoulders and back. Inhabiting interior areas such as Yellowstone or Denali, grizzlies forage for plants such as grasses, glacier lilies, whitebark pinenuts, biscuit root, horsetail, false truffles, clover, dandelions, spring-beauty and globe huckleberries. They fish cutthroat trout from streams and eat worms, moths and ants. They also scavenge the carcasses of wolf kills and prey upon elk calves and the occasional bison.

Brown bears in Alaska digging for clams on the tidal flats.

© Brad Josephs

Meanwhile, coastal brown bears have a fatty, salmon-rich diet, which is why those found along the Alaska Peninsula are the largest in the world. While all brown bears are resourceful, opportunistic feeders, vegetation play a much smaller role in the feeding habits of bears living along the shoreline. They will, however, supplement their diet with razor, butter and steamer clams they dig up on the tidal flats, as well as sedges, flowers, roots and berries.

Because a large bulk of their diet is vegetarian, grizzlies tend to be smaller than their relatives on the coast, who feast on the bounty of salmon runs. Brown bears on the shores of Alaska can reach massive proportions, weighing up to 1,650 pounds and standing 9 feet tall on hind feet. Bears that lack these marine reserves weigh far less, typically between 200 and 700 pounds. In addition to variations in size, it has been suggested that there are temperamental differences. Due to competition over a less abundant food supply and the need for a more extensive home range, inland grizzlies seem to react more aggressively to other bears and humans.

Brown bear catches a salmon in Alaska.

© Mona Wong

Brown bear catches a salmon in Alaska.

© Benjamin Spalding

Katmai National Park is home to approximately 2,200 colossal brown bears. Watch these mighty giants fish for spawning salmon and forage in flowery meadows on Natural Habitat Adventure’s Wild Alaska Grizzly Encounter and Ultimate Alaska Wildlife Safari.

Nat Hab travelers with brown bears in Alaska.

© Alek Komarnitsky