12 julio, 2024

Kodiak Bear: Characteristics, Habitat, Feeding, Behavior

He kodiak bear (Ursus arctos middendorffi) is a placental mammal that is part of the Ursidae family. Its body is strongly built, with short legs and non-retractable claws. On the back, between both shoulders, it has a hump, formed by a group of muscles. These give the front limbs extreme strength.

As for coloring, it can be from dark brown to blonde tones. The coat is made up of two types of hair, one protective and the other low. Both work as thermal insulators, preventing cold and water from altering the values ​​of internal body temperature.

He Ursus arctos middendorffi It presents sexual dimorphism, with the males being larger and heavier than the females. Thus, these have an approximate length of 244 centimeters and an average body mass of 505 kilograms, although they could weigh up to 751 kilograms.

The Alaskan brown bear, as this subspecies of the brown bear is also known, is distributed on the islands of the Kodiak Archipelago, southwest of Alaska. This mammal is not listed in the NICU. However, it has state legislation, which protects its development within the natural habitat it occupies.


Kodiak Bear Characteristics


The Kodiak bear has a large head with small round ears. It has powerful teeth and a strong jaw, which allow it to cut through the flesh, bones, and skin of its prey.

In relation to the skull, it is wide. In bears, this bone structure is the last to stop growing. In it Ursus arctos middendorffi, the female’s skull reaches a maximum size when she is 8 years old. In relation to the male, it grows until she is between 10 and 12 years old. In the adult, it can measure up to 78 centimeters.


This subspecies has a stocky body and strong, short limbs. Between the shoulders it has a hump, made up of an important group of muscles. These, together with the claws and powerful skeleton, make its front limbs very strong.

Thus, the Kodiak bear can run down a slope, dig a den, or flip heavy rocks. In addition, said musculature provides the animal with powerful striking force in the front legs.


One of the most important senses is smell. With this you can locate your prey, your partner and detect a predator. Another highly developed organ is the ear.

Although their ears are small in size compared to their head and body, they can pick up sounds from distant places. Regarding sight, recent studies show that the Kodiak bear is not myopic, as was believed. Also, this mammal can distinguish colors.

To expand the field of vision of the space where it is located, the bear usually stands up on its two hind legs. Although this posture could be associated with aggressive behavior, the animal is trying to obtain more sensory information from the environment.


The fur of the Ursus arctos middendorffi it can range from a shade of dark brown to almost blonde. Generally the tone of the face is usually a little lighter than the rest of the body. Also, it presents different characteristics during the seasons of the year and in the various stages of development.

Thus, when the thick winter coat begins to grow, the color darkens. In addition, the older species frequently have a darker coloration than the young.

As for the puppies, they often have a white band around the shoulder and neck. This collar fades progressively over time, having completely disappeared by the age of 4 or 5 years.

The fur of the Kodiak bear is an excellent insulator. It is formed by two types of hairs, the under and the guard. In addition, it has an oily texture that, together with its high density, keeps the animal warm and prevents water from penetrating the skin.

Annually, naturally, they change their hair. However, to contribute to this elimination, the animal rubs its body against the trunk of the trees and against the rocks. As the fur falls off, the new one supplants it.


The claws are not retractable and can measure up to 10 centimeters. The young are dark brown, but this tone lightens with age.

Bears use them to defend themselves and to attack other bears, but mainly to dig, build burrows and search for food. The cubs can use their claws to climb trees, but the adult cannot climb them due to its body weight.


This subspecies can quickly run short distances, reaching speeds between 56 and 65 km/h. Also, it is an excellent swimmer, being able to swim across a lake or bay up to 3.2 kilometers long. It can often dive to cool its body or to hunt salmon.


The Kodiak bear is sexually dimorphic, with females being up to 20% smaller and around 30% lighter than males. Thus, these measure an average of 244 centimeters long and 133 centimeters high at the shoulder. Its weight ranges between 477 and 534 kg, and can reach up to 751 kg.

In relation to females, they have an approximate body mass of 181 to 318 kilograms. When the animal is in the winter den it loses weight, being able to increase it by 20 or 30% during the last months of summer or autumn.


In the Kodiak Archipelago, during the winter, weather conditions become adverse and the atmospheric temperature drops. This results in, among other things, food shortages. Because of this, the Ursus arctos middendorffi it hibernates at that time of year, intent on conserving its energy.

On Kodiak, the winter season is relatively mild, so this subspecies can drift in and out of the organic state of hibernation. Even some adult male bears do not hibernate.

The entrance to the lair has a pre-established order. Thus, first the pregnant females enter, then the females that are alone and later the mothers and their cubs. As for the males, the young enter first than the adults and the old.

Regarding the exit from the refuge, this depends on the climatic characteristics and presents variations according to age and sex. Males are usually the first to emerge, followed by females without pups, and then adults with pups.

Regarding time, males usually last between 3 and 5 months in hibernation, while pregnant females could hibernate for up to 7 months.

organic changes

During the fall, the Kodiak bear increases its intake of elderberries, which provide it with natural sugars, and salmon, a protein-rich food. In this way, they increase the thickness of the fat layer by approximately 15 to 21 centimeters.

This adipose tissue serves as a source of nutrients during hibernation, since bears do not eat or drink water during this time. When inside the shelter, they huddle together to keep warm. However, they can wake up, move around, and even temporarily leave the burrow.

While this subspecies is hibernating, respiration slows, from 10 breaths per minute to 1 every 45 seconds. Also, the heart rate drops, from 50 beats per minute to 19 beats per minute. However, the body temperature drops slightly, remaining within the appropriate range for their survival.


-Animal Kingdom.

-Subkingdom: Bilateria.

-Filum: Chordate.

-Subfulim: Vertebrate.

-Superclass: Tetrapoda.

-Class: Mammal.

-Subclass: Theria.

-Infraclass: Eutheria.

-Order: Carnivora.

-Suborder: Caniformia.

-Family: Ursidae.

-Genre: Ursus.

-Species: ursus arctos.

-Subspecies: Ursus arctos middendorffi.

hhabitat and distribution

The Kodiak bear is found only on the islands of the Kodiak Archipelago, southwest of Alaska. Thus, it is found on Afognak, Kodiak, Shuyak, Uganik, Raspberry, Sitkalidak and on the adjacent islands. In this way, this subspecies of the brown bear lives on approximately 5,000 square miles of islands.

The climate is subpolar oceanic, with low temperatures, strong to moderate winds, and rainfall for much of the year. It has a highly varied topography, and the vegetation includes dense forests of Sitka spruce (spruce sitchensis), glacial mountains, up to 1,360 meters, and tundras.

This subspecies lives throughout the archipelago, where it adapts to the various natural resources that are present. Thus, to the north and east it has a dense forest cover, with abundant streams and to the south, the region lacks trees. In addition, between the islands there are small glaciers.

home ranges

On Kodiak Island, the foods that make up the diet of the Ursus arctos middendorffi. Because of this, the home range is smaller in size than any other of its genus.

Also, females often have smaller ranges than males. In this sense, the area occupied annually by females averages 130 km2 and that of males is 250 km2.

On the other hand, subadult females establish areas within, or overlapping, the mother’s home range. Young males generally travel great distances to establish an area to live.

Specialists have carried out studies regarding the relationship between domestic ranges and movements of Kodiak bears, associated with food sources. One of these was carried out in the areas surrounding Lake Karluk, where these animals move between different drainages.

These movements are synchronized with the arrival of the salmon in the stream, an aspect that does not have a specific date of occurrence, thus varying each year.


According to experts, mothers teach their pups how to choose shelter. In the Kodiak Archipelago, few natural caves exist, so bears have to dig their dens. They do this on the sides of snowbanks or mountains.

Thus, those who inhabit the north may choose steep alpine slopes, while those in the southwest prefer habitats with a medium slope, close to alder scrub. These shelters are destroyed during the spring and fall, so the Kodiak bear is forced to dig a new one the following fall.

State of conservation

He Ursus arctos middendorffi It is not included on the IUCN list, nor on the US Fish and Wildlife Service Endangered Species Act list of endangered species.

This subspecies is heavily protected by the federal government. This has progressively caused the populations of the Kodiak bear to increase.

Their hunting is controlled by a highly organized system, where only 496 permits are authorized annually. These are distributed in 32 different regions, during the autumn and spring seasons.

Within the regulations, it is established that non-resident hunters must hire a registered guide, which could cost between 10,000 and 22,000…

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