Kodiak bear
The Kodiak bear, also known as the Kodiak brown bear and sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is one of the largest recognized subspecies or population of the brown bear, and one of the two largest bears alive today, the other being the polar bear. They are also considered by some to be a population of grizzly bears.
Physiologically and physically, the Kodiak bear is very similar to the other brown bear subspecies, such as the mainland grizzly bear and the extinct California grizzly bear, with the main difference being size, as Kodiak bears are on average 1.5 to 2 times larger than their cousins. Despite this large variation in size, the diet and lifestyle of the Kodiak bear do not differ greatly from those of other brown bears.
Kodiak bears have interacted with humans for centuries, especially hunters and other people in the rural coastal regions of the archipelago. The bears are hunted for sport and are encountered by hunters pursuing other species. Less frequently, Kodiak bears are killed by people whose property or person are threatened. In recent history there has been an increasing focus on conservation and protection of the Kodiak bear population as human activity in its range increases. The IUCN classifies the brown bear '', of which the Kodiak is a subspecies, as being of "least concern" in terms of endangerment or extinction, though the IUCN does not differentiate between subspecies and thus does not provide a conservation status for the Kodiak population. The Alaska Department of Fish and Game, along with the United States Fish and Wildlife Service to a lesser extent, closely monitor the size and health of the population and the number of bears hunted in the state.
Description
Taxonomy
Taxonomist C.H. Merriam was the first to recognize the Kodiak bear as a unique subspecies of the brown bear, and he named it "Ursus middendorffi" in honor of the celebrated Baltic naturalist, Dr. A. Th. von Middendorff. Subsequent taxonomic work merged all North American brown bears into a single species.Genetic samples from bears on Kodiak have shown that they are most closely related to brown bears on the Alaska Peninsula and Kamchatka, Russia, and all brown bears roughly north of the US. Kodiak bears have been genetically isolated since at least the last ice age and very little genetic diversity exists within the population. Although the current population is healthy, productive, and has shown no overt adverse signs of inbreeding, it may be more susceptible to new diseases or parasites than other, more diverse brown bear populations.
Color
Hair colors range from pale blonde to orange to dark brown. Cubs will often retain a white "natal ring" around their neck for the first few years of life. The Kodiak bear's color is similar to that of its close relatives, the mainland American Grizzly bear and Eurasian brown bears.Size
While there is generally much variation in size between brown bears in different areas, most usually weigh between 115 and 360 kg ; the Kodiak bear illustrates island gigantism, commonly reaching sizes of. The size range for females is from, and for males, it is. Mature males average over the course of the year, and can weigh up to at peak times. Females are typically about 20% smaller and 30% lighter than males, and adult sizes are attained when they are six years old. Bears weigh the least when they emerge from their dens in the spring, and can increase their weight by 20–30% during late summer and autumn. As with other animals, captive Kodiak bears can sometimes weigh considerably more than their wild counterparts.An average adult male measures in length, and stands tall at the shoulder. The largest recorded wild male weighed, and had a hind foot measurement of. A large male Kodiak bear stands up to tall at the shoulder when it is standing on all four legs. When standing fully upright on its hind legs, a large male could reach a height of. The largest verified size for a captive Kodiak bear was for a specimen that lived at the Dakota Zoo in Bismarck, North Dakota. Nicknamed "Clyde", he weighed when he died in June 1987 at the age of 22. According to zoo director Terry Lincoln, Clyde probably weighed close to a year earlier. He still had a fat layer of when he died..
Kodiak bears are the largest brown bear and are even comparable in size to polar bears. This makes Kodiak bears and polar bears the two largest members of the bear family and the largest extant terrestrial carnivorans.
The standard method of evaluating the size of bears is by measuring their skulls. Most North American hunting organizations and management agencies use calipers to measure the length of the skull, and the width. The total skull size is the sum of these two measurements. The largest bear ever killed in North America was from Kodiak Island, with a total skull size of, and eight of the top 10 brown bears listed in the Boone and Crockett record book are from Kodiak. The average skull size of Kodiak bears that were killed by hunters in the first five years of the 21st century was for boars, and for sows.
Also, an individual named Teddy, which portrayed a killer bear in the movie Grizzly, stood tall on its hind legs and was the largest bear in captivity at the time.
Life history
Distribution and density
This brown bear population occurs only on the islands of the Kodiak Archipelago. The Kodiak bear population was estimated to include 3,526 bears in 2005, yielding an estimated archipelago-wide population density of 270 bears per 1000 km2. During the past decade , the population has been slowly increasing.Home range
Bears on Kodiak are naturally active during the day, but when faced with competition for food or space, they adopt a more nocturnal lifestyle. This behavior is especially evident in the bears that live near and within Kodiak City. Kodiak bears do not defend territories, but they do have traditional areas that they use each year. Because of the rich variety of foods available on Kodiak, the bears on the archipelago have some of the smallest home ranges of any brown bear populations in North America and a great deal of overlap occurs among the ranges of individual bears. Home ranges of adult sows on Kodiak Island average, while boar home ranges average.Denning
Kodiak bears begin entering their dens in late October. Pregnant sows are usually the first to go to dens; males are the last. Males begin emerging from their dens in early April, while sows with new cubs may stay in dens until late June. Bears living on the north end of Kodiak Island tend to have longer denning periods than bears in the southern areas. Most Kodiak bears dig their dens in hill or mountain sides and they use a wide variety of denning habitats depending on which part of the archipelago they live. Almost a quarter of the adult bears forgo denning, staying somewhat active throughout the winter.Reproduction and survival
Kodiak bears reach sexual maturity at age five, but most sows are over nine years old when they successfully wean their first litter. The average time between litters is four years. Sows continue to produce cubs throughout their lives, but their productivity diminishes after they are 20 years old. Mating season for Kodiak bears is during May and June. They are serially monogamous, staying together from two days to two weeks. As soon as the egg is fertilized and divides a few times, it enters a state of suspended animation until autumn when it finally implants on the uterine wall and begins to grow again. Cubs are born in the den during January or February. Weighing less than at birth with little hair and closed eyes, they suckle for several months, emerging from the den in May or June, weighing. Typical litter sizes on Kodiak are two or three cubs, with a long-term average of 2.4 cubs per litter. However, Kodiak bears have six functional nipples and can litter up to six cubs reportedly. Sows are sometimes seen with five or six cubs in tow, probably due to adopting cubs from other litters. Most cubs stay with their mothers for three years. Almost half of the cubs die before they leave, with cannibalism by adult males being one of the major causes of death.Kodiak bears that have recently left their mothers, at ages 3–5 years, have high mortality rates with roughly 56% of males and 89% of females surviving. Most young female bears stay within or near their mother's home range, while most males move farther away. Most adult sows die of natural causes, while most adult male bears are killed by hunters. The oldest known male bear in the wild was 27 years old, and the oldest female was 35.