Brown Bear in Alaska

The brown bear (Ursus arctos) is a large bear found across most of Alaska, where the population is estimated at about 30,000, the largest share of the roughly 32,500 brown bears in the United States. Coastal bears that feed on salmon, including the Kodiak bears of the Kodiak Archipelago, grow much larger than interior bears, which are often called grizzlies. Males can weigh 500 to 900 pounds in fall, and some reach 1,400 pounds [1][2].

Description

Adults stand about 3.5 feet tall on all fours and measure just over seven feet in body length. They have a shoulder hump and a dish-shaped face [1]. Brown bears generally weigh 80 to 600 kilograms (180 to 1,320 pounds), and males are at least 30 percent larger than females. Coastal populations weigh about twice as much as interior bears: interior males average about 400 pounds and interior females about 298 pounds [2].

Range and Habitat

Brown bears live throughout Alaska except on certain southeastern islands, the western Aleutians and the Bering Sea islands [1]. The Kodiak Archipelago population has probably been isolated since the end of the last Ice Age [2]. Home range depends on food. Adult males in the Brooks Range average about 521 square miles, while bears in salmon-rich coastal areas need only about 10.5 square miles, and ranges often overlap because brown bears generally do not defend them [1].

Diet

Over 75 percent of the diet is plant matter, such as berries, flowers, grasses, herbs and roots, with the rest from carrion, fish, insects, moose calves and small mammals. In summer and early fall a bear eats 80 to 90 pounds of food a day and gains three to six pounds of fat daily [1]. Coastal bears get much of their protein from salmon, which contributes to larger size and darker coats compared to interior bears [1][2]. Along estuary beaches they dig for clams, and in Denali National Park they hunt Arctic ground squirrels at burrow entrances [2].

Hibernation

Hibernation lasts five to eight months in the coldest parts of the range, while bears in warmer areas such as Kodiak Island may remain active through winter. Cubs are born in January or February while the mother is still in the den and leave it in April or May. Females can delay implantation of the embryo if fat reserves are low [1]. Bears are not full hibernators and can be woken easily; they may gain up to about 400 pounds of fat from summer through autumn [2].

Reproduction and Lifespan

Females mature between ages 4 and 8. Mating runs from mid-May to early July, litters are usually one to three cubs, and cubs stay with their mother for about 2.5 years on average in North America [2]. Males typically live to about 22 and females to about 26, though a few live up to 34 years in the wild [1].

Senses and Behavior

Brown bears are opportunistic feeders. They can run up to 35 miles per hour over short distances and may detect odors more than a mile away, while their hearing and eyesight are comparable to human senses [1].

Management and Hunting

Brown bears can be legally hunted in Alaska with a license, but cubs and females with cubs may not be taken [1][2]. The Kenai Peninsula population, estimated at 250 to 300 bears, is designated a Species of Special Concern [1].

Viewing Bears in Alaska

Coastal salmon streams and parks such as Katmai and Kenai Fjords are well known areas where brown bears are found [1]. Visitors should follow park guidance and keep food secured.

FAQs

How many brown bears are in Alaska? Estimates are about 30,000.

Are Kodiak bears brown bears? Yes. Kodiak bears are brown bears of the Kodiak Archipelago, isolated since the last Ice Age.

What do brown bears eat in Alaska? Mostly plants, plus salmon, carrion, insects and small mammals.

How big do Alaska brown bears get? Males typically 500–900 pounds in fall; some reach 1,400 pounds.

How long do brown bears hibernate? Five to eight months in the coldest parts of their range.

Sources

1. National Park Service: Brown Bear, Kenai Fjords National Park
2. Wikipedia: Brown bear

Editorially reviewed by Specialty Digest Editorial TeamLast reviewed November 12, 2026Researched and drafted with AI assistanceReport an issue