AnimalTracks.wiki

What the sources say

Kodiak BearUrsus arctos middendorffi

Every figure, record and mechanism on the Kodiak Bear profile was written from a source, and this is the working table behind it: 64 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.

Profile updated

Source
01

U.S. Fish & Wildlife Service, Species Profile

Kodiak Brown Bear (Ursus arctos middendorffi). U.S. Fish & Wildlife Service, Species Profile.

The page saysadult males weighing 600 to 1,400 pounds
The source saysAdult males are 600 to 1,400 pounds (272 to 635 kilograms)
The page saysstanding up to ten feet on their hind legs
The source saysup to 10 feet (3 meters) tall when upright
The page saysSitka spruce forest, glaciated mountains, and tundra across the Kodiak Archipelago
The source saysFrom the dense forests of Sitka spruce on the northern islands, to steep, glaciated mountains ... to rolling hills and flat tundra on the south end
The page saysSalmon, sedges and berries
The source saysprimarily consume vegetation like sedges, forbs and berries, as well as salmon
The page saysclams and marine mammal carcasses found among the kelp on beaches
The source saysflat open beaches patrolling for marine mammal carcasses, clams or invertebrates among the kelp
The page saysLoses 20 to 40% of its body mass during hibernation
The source sayslose 20 to 40% of their body mass during hibernation
The page saysCoastal Heavyweights
The source saysKodiak brown bears and other coastal brown bears can weigh about twice as much as interior brown bearsNote: the heading names no figure or comparison; adult males weigh 600 to 1,400 pounds on the same page
The page saysis a subspecies of brown bear that lives only on Alaska's Kodiak Archipelago
The source saysis a subspecies of brown bear that only exists on the Kodiak Archipelago, which includes Kodiak Island and the surrounding islands of Afognak, Shuyak, Raspberry, Uganik, Sitkalidak and others, in Alaska.
The page saysIt stands 3 to 5 feet (0.9 to 1.5 meters) high on all fours
The source saysThe Kodiak brown bear is a large bear, 3 to 5 feet (0.9 to 1.5 meters) high while on all fours
The page saysup to 10 feet (3 meters) tall upright
The source saysup to 10 feet (3 meters) tall when upright
The page saysAdult males weigh 600 to 1,400 pounds (272 to 635 kilograms)
The source saysAdult males are 600 to 1,400 pounds (272 to 635 kilograms)
The page saysadult females 300 to 700 pounds (136 to 318 kilograms)
The source saysAdult females are 300 to 700 pounds (136 to 318 kilograms)
The page saysThe Boone and Crockett Club's world-record bear is a Kodiak brown bear, with a skull measuring 30.75 inches (78.1 centimeters) in width plus length
The source saysThe Boone and Crockett Club world-record bear is a Kodiak brown bear with a skull measuring 30.75 inches (78.1 centimeters; width + length).
The page saysKodiak bears are thought to have diverged from their brown bear relatives around 12,000 years ago, after becoming geographically isolated at the end of the last ice age
The source saysThe Kodiak bear is thought to have diverged from its brown bear relatives, most likely Alaska Peninsula and Kamchatka Russia populations, around 12,000 years ago after becoming geographically isolated at the end of the last ice age.
The page saysSome research suggests the genetic and size differences between them and other Alaskan brown bears are minimal, and that environment and food supply could largely explain the size differences
The source saysSome research, however, suggests that genetic and size differences between Kodiak bears and other Alaskan brown bears are minimal. That research contends that phenotypic plasticity, meaning the ability of individuals to reach different body types depending on the environment, and resource availability ... could largely explain size differences.
The page saysStill, genetic diversity within the Kodiak population is the lowest of any recorded North American brown bear population, a major conservation concern
The source saysStill, it is apparent that genetic diversity within the Kodiak population is the lowest of any recorded North American brown bear population, and is a major conservation concern.
The page saysDense Sitka spruce forest grows on the northern islands, glaciated mountains rise to 4,470 feet (1,360 meters) along the central spine of Kodiak Island, and the south end has rolling hills and flat tundra
The source saysFrom the dense forests of Sitka spruce on the northern islands, to steep, glaciated mountains that rise to 4,470 feet (1,360 meters) along the central spine of Kodiak Island, to rolling hills and flat tundra on the south end
The page saysBears are most often seen on low-elevation salt marshes in spring and on salmon streams or berry patches in summer
The source saysThey are most commonly seen using seasonal resources on low-elevation salt marshes in the spring and salmon streams or berry patches in the summer.
The page saysthey travel the beaches patrolling for marine mammal carcasses, clams or invertebrates among the kelp
The source saysflat open beaches patrolling for marine mammal carcasses, clams or invertebrates among the kelp
The page saysSalmon makes up about 64% of a Kodiak bear's diet, and plant matter such as sedges, forbs and berries another 26%
The source saysDiet analyses show that they primarily consume vegetation like sedges, forbs and berries, as well as salmon. Salmon makes up about 64% of their diet, with another 26% being plant matter.
The page saysAn estimated 3,500 bears live on the archipelago
The source saysThere are an estimated 3,500 Kodiak brown bears on the Kodiak Archipelago
The page saysCrowds on the Salmon Streams
The source saysWhen food resources are abundant, such as on salmon streams, localized densities of bears can be especially high
The page saysKodiak bears communicate mainly with body language and are therefore quiet much of the time
The source saysBears communicate primarily using body language and are therefore quiet much of the time.
The page saysOn salmon streams they function within strict social hierarchies
The source saysWhen food resources are abundant, such as on salmon streams, localized densities of bears can be especially high and bears function within strict social hierarchies.
The page sayslarge males are often dominant, but females can also hold top positions
The source saysLarge males are often dominant, but females can also hold top positions.
The page saysThey sometimes huff, a quick exhale of air, in a surprise encounter with a person or another bear, or to warn their cubs of danger
The source saysbears will sometimes huff , which isa quick exhaling of air, during a surprise encounter with a human or other bear, or to signal danger to their cubs.
The page saysMonths in the Den
The source saysMost bears spend a little more than half of the year active, searching for salmon, berries or other important foods, and spend the remainder of the year denning.
The page saysBrown bears lose 20 to 40% of their body mass during hibernation
The source saysBrown bears are heaviest just before hibernation in the fall, lose 20 to 40% of their body mass during hibernation
The page saysOn Kodiak, bears typically begin denning in early to mid-November
The source saysIn Kodiak, bears typically begin denning in early to mid-November.Note: the older Van Daele fact sheet says 'late October'; the current FWS page wins
The page saysweighing less than a pound and unable to walk or see
The source saysweigh less than a pound at birth and are born unable to walk or see
The page saysThe average litter has 2.4 cubs
The source saysThe average litter has 2.4 cubs
The page saysthey stay with their mother for 2 to 3 years before she drives them off to live on their own
The source saysCubs stay with their mother for 2 to 3 years before mothers drive them off to live on their own.
The page saysKodiak brown bears are considered old at 20
The source saysWhile a 20 years of age is considered old for a Kodiak brown bear
The page saysthey can live past 30 years in the wild and past 40 in captivity
The source saysthey can live past 30 years in the wild and past 40 years in captivity.
The page saysKodiak brown bears and other coastal brown bears can weigh about twice as much as interior brown bears, which are known as grizzly bears
The source saysKodiak brown bears and other coastal brown bears can weigh about twice as much as interior brown bears, which are referred to as grizzly bears.
The page saysAdult male Kodiak bears weigh 600 to 1,400 pounds (272 to 635 kilograms)
The source saysAdult males are 600 to 1,400 pounds (272 to 635 kilograms)
The page sayscan stand up to 10 feet (3 meters) tall on their hind legs
The source saysup to 10 feet (3 meters) tall when upright
The page saysSome research, though, suggests the genetic and size differences between Kodiak bears and other Alaskan brown bears are minimal
The source saysSome research, however, suggests that genetic and size differences between Kodiak bears and other Alaskan brown bears are minimal.
The page saysenvironment and food, such as the abundance of protein-rich foods, could largely explain the size differences
The source saysdepending on the environment, and resource availability, for example the abundance of protein-rich foods, could largely explain size differences.
The page saysAlmost anything they can find
The source saysKodiak brown bears are omnivores and opportunists, eating both plant and animal matter, and consuming almost anything they can find.
The page saysSalmon makes up about 64% of a Kodiak bear's diet, and plant matter such as sedges, forbs and berries another 26%
The source saysDiet analyses show that they primarily consume vegetation like sedges, forbs and berries, as well as salmon. Salmon makes up about 64% of their diet, with another 26% being plant matter.
The page saysDeer, mountain goats and elk live on the island but do not make up a substantial part of the diet
The source saysAlthough deer, mountain goats and elk are present on the island, they do not make up a substantial portion of the diet.
The page saysKodiak bears also occasionally eat marine mammals and invertebrates, birds and their eggs, rodents and human food
The source saysKodiak brown bears are also known to occasionally consume marine mammals and invertebrates, as well as birds and their eggs, rodents and anthropogenic, meaning human-origin foods.
The page saysThrough body language and a pecking order
The source saysBears communicate primarily using body language and are therefore quiet much of the time.Note: the pecking order is the same page's 'bears function within strict social hierarchies', quoted for the next sentence
The page saysBears communicate mainly with body language and are therefore quiet much of the time
The source saysBears communicate primarily using body language and are therefore quiet much of the time.
The page saysWhere food is abundant, such as on salmon streams, bears can gather at especially high densities and function within strict social hierarchies
The source saysWhen food resources are abundant, such as on salmon streams, localized densities of bears can be especially high and bears function within strict social hierarchies.
The page sayslarge males are often dominant but females can also hold top positions
The source saysLarge males are often dominant, but females can also hold top positions.
The page saysIn a conflict, bears are more likely to make noise
The source saysDuring conflict, they are more likely to make noise.
The page saysjaw-popping, a clacking noise made by opening and closing the jaw in a specific way, can signal nervousness or agitation
The source saysJaw-popping, which is a clacking noise that accompanies bears opening and closing their jaw in a specific way, can signal nervousness or agitation
The page sayssized to a bear whose adult males weigh 600 to 1,400 pounds
The source saysAdult males are 600 to 1,400 pounds (272 to 635 kilograms)Note: vibe.reason: the pairing now rests on mass, not on geography

Source
02

Kodiak National Wildlife Refuge, U.S. Fish & Wildlife Service

Species. Kodiak National Wildlife Refuge, U.S. Fish & Wildlife Service.

The page saysIsolated on one Alaskan island chain for about twelve thousand years
The source saysthey have been isolated on the archipelago since the last ice age, about 12,000 years ago.
The page saysIslands Stacked With Food
The source saysA rich variety of vegetation, salmon, and berries provide ideal habitat for bears
The page saysthe Karluk Lake drainage has one of the densest bear populations in the world
The source saysKodiak's Karluk Lake drainage has one of the densest populations of bears in the world.

Source
03

Alaska Department of Fish and Game, Wildlife Notebook Series

Brown Bear. Alaska Department of Fish and Game, Wildlife Notebook Series.

The page sayswithout eating, drinking, urinating or defecating in the den
The source saysWhile in the den they do not eat, drink, urinate or defecate.Note: the notebook (revised 2025) covers all Alaska brown bears, Kodiak bears included
The page saysa large male brown bear in coastal areas may weigh up to 1,500 pounds (680 kilograms)
The source saysA large male may weigh up to 1,500 lbs (680 kg) in coastal areasNote: notebook revised 2025, covering all Alaska brown bears; the Van Daele fact sheet's Kodiak-only 'up to 1,500 pounds' is older (circa 2010) and no longer cited
The page saysBrown bears are generally solitary but often gather in large groups at feeding areas such as salmon spawning streams
The source saysAlthough generally solitary in nature, brown bears often occur in large groups in concentrated feeding areas such as salmon spawning streams
The page saysbecause of this they have developed a complex language and social structure to minimize serious fights
The source saysBecause of this, they have developed a complex language and social structure to express their feelings and minimize serious fightsNote: notebook revised 2025; the older Van Daele fact sheet said 'avoid fights', and the current wording wins
The page sayswhile in the den they do not eat, drink, urinate or defecate
The source saysWhile in the den they do not eat, drink, urinate or defecate.
The page saysalthough in its relatively mild winters some males stay active all winter
The source saysin areas with relatively mild winters, such as Kodiak, some male bears stay active all winter.

Source
04

Van Daele, L.

Van Daele, L.. Kodiak Bear Fact Sheet. Alaska Department of Fish and Game.

The page saysKodiak cubs are born in the den in January or February
The source saysCubs are born in the den during January or February.

Source
05

Sommer et al. 2016

Sommer et al. (2016). The Gut Microbiota Modulates Energy Metabolism in the Hibernating Brown Bear Ursus arctos. Cell Reports.

The page saysObese but Healthy
The source saysAlthough bears seasonally become obese, they remain metabolically healthy.
The page saysBrown bears double their fat stores during summer and use that stored fat during hibernation
The source saysBrown bears double their fat depots during summer and use these stored lipids during hibernation.
The page saysThey become seasonally obese, yet remain metabolically healthy
The source saysAlthough bears seasonally become obese, they remain metabolically healthy.

Source
06

Huber 2025

Huber (2025). Ursus arctos. The IUCN Red List of Threatened Species 2025: e.T41688A216873475.

The page saysLeast Concern
The source saysIUCN Red List category: Least Concern (LC).Note: the assessment covers the species Ursus arctos; the Kodiak subspecies has no separate Red List assessment

How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.