Kodiak Bear
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- "Alaskan Brown Bear" redirects here.
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| Ursus arctos middendorffi (Ord, 1815) |
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 Kodiak bear distribution map
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The Kodiak bear (Ursus arctos middendorffi) is a unique subspecies of the brown bear. Kodiak bears live exclusively on the islands in the Kodiak Archipelago and have been isolated from other bears for about 12,000 years.[1]
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[edit] Population
There are about 3,500 Kodiak bears, an average population density of 285 bears per 1,000 square kilometers (0.7 bears per square mile). Kodiak bear populations are healthy and productive. They enjoy relatively pristine habitat and well managed fish populations. In most areas the number of bears is stable, but there are some places where bear density is increasing [2].
[edit] Size and appearance
Kodiak bears are generally considered to be among the largest of all terrestrial bears, being comparable in size to the Polar Bear. Altogether, sixteen of the twenty largest brown bears killed by hunters have come from the archipelago. A large male can stand over 3 meters (10 ft) tall when on his hind legs, and 1.5 meters (5 ft) tall when on all four legs. [1]
Boars (male bears) can weigh over 700 kg (1,500 lbs) after feeding on spawning salmon.[2] Sows (females) are about 20 percent smaller, and 30 percent lighter than boars. Kodiak bears in captivity can reach substantially greater weights than their wild relatives.
The largest known Kodiak bear in captivity was named "Clyde" and lived at the Dakota Zoo in Bismarck, ND. According to Terry K. Lincoln, present zoo director[3]:
Clyde was a Kodiak Bear that (as I understand it) was a radio collared young bear that came from Kodiak Island. I understand that he was somehow acclimated to humans and that's why he was removed from the wild. Clyde weighed 2130 lbs. at his death in 1987, at the age of 22. He probably weighed closer to 2400 a year or so before he died. Clyde was very obese due to lots of donuts and other sweets. (That's how they did it back then.) I was present at his necropsy and he had a fat layer (in June) of about 9". Our bears today, both of which are brown bears, weigh closer to 1000 lbs. and are very healthy...they don't get donuts, just food that is good for them. There is a redwood carved statue in memory of Clyde in our Discovery Center.
[edit] Behaviour
[edit] Social
Although generally solitary in nature, Kodiak bears often occur in large groups in concentrated feeding areas. Because of this, they have developed a complex language (vocalizations and body postures) and social structure [3] to express their feelings and avoid fights. Alaska Department of Fish and Game records (2007) indicate that only one person has been killed by a bear on the Kodiak Archipelago in the past 80 years, and on the average only about once every other year a person was injured by a bear on the Archipelago.
[edit] Life History
Mating season for Kodiak bears is during May and June. They are serially monogamous (having one partner at a time), staying together for a couple days or a couple 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 a pound at birth with little hair and closed eyes, they suckle for several months, emerging from the den in May or June, weighing 7-9 kg (15-20 lbs). Typical litter sizes are 2-3 cubs. Sows are sometimes seen with 5 or 6 cubs in tow, probably due to adopting cubs from other litters. Most cubs stay with their mothers for 3 years. Over 25% of the cubs die before they leave, with cannibalism by adult males being one of the major causes of death.
Bears that have recently left their mothers, at ages 3-5, have a high mortality rate as they face the world on their own. Some of these subadults are the “juvenile delinquents” of bear society and are also the ones most likely to cause problems with people. Kodiak bears become sexually mature at age 5 and can continue to produce cubs throughout their lives. The average interval between litters is about 4 years. The oldest known wild Kodiak bear was a 34-year-old sow. The oldest boar was 27.
Kodiak bears begin entering their dens in late October. Pregnant sows are 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. Some males forego denning, staying awake all winter. Medical researchers are very interested in denning physiology. They are trying to determine how bears can sleep for up to 8 months without eating, drinking, urinating or defecating, yet when they awaken they have lost little bone mass or muscle tone and have no signs of uremia.
Bears on Kodiak are naturally diurnal (active during the day), but when faced with competition for food or space, they adopt a more nocturnal (active at night) life style. They do not defend territories, but they do have traditional areas that they use each year (home ranges). Because of the rich variety of foods available on Kodiak, bears here have some of the smallest home ranges of any brown bear population.
[edit] Diet
Though Kodiak bears are often touted as the world's largest land carnivore, they are really omnivores. They actually spend more time eating grass, plants and berries than meat. Fish are an important part of their diets, but few Kodiak bears expend the time or effort necessary to chase and kill mammals. They use the most nutritious parts of their food to maximize their weight gain. Grass and forbs are only used while they are rapidly growing in the spring and early summer. Brains, flesh and eggs are preferred parts of the salmon. Internal organs of deer, elk and cattle are eaten first when one is killed or scavenged. Berries are used most often when they are ripe and sugars are at their highest level.
[edit] Conservation
Traditionally, Kodiak Natives (Alutiiqs) hunted bears for food, clothing and tools. Arrows, spears, and a great deal of courage were required hunting equipment. Bear heads were usually left in the field as a sign of respect to the spirit of the bears. Kodiak bears were commercially hunted throughout the 1800s with the price paid for a bear hide being comparable to that paid for a beaver or river otter pelt (about $10)[4].
Bears and cattle ranchers have waged an ongoing battle for the past 200 years. Original Russian settlers were encouraged to bring large aggressive dogs to protect cattle from bears. As early as the 1930s, biologists and ranchers were exploring ways to reduce the number of cattle killed by bears. At one point bears were shot from airplanes, and a 9-foot high bear fence was proposed to bisect Kodiak Island and create a “bear-free zone.” All active efforts at bear control in Kodiak ended in the mid-1960s[4].
Concern over reduced bear populations prompted sportsmen to petition the Federal government to protect bears and their habitat on Kodiak. The results of their efforts were stricter regulations and creation of Kodiak National Wildlife Refuge in 1941.
Today hunters kill about 160 Kodiak bears each year under tightly controlled regulations. About 5,000 Alaska resident hunters apply each year for a chance at the 319 bear permits that are available for them. Hunters who are not residents of Alaska must hire a professional guide, paying $10,000 – $15,000 per hunt. Over 70% of the Kodiak bears killed by hunters are males. Kodiak bear research, management, and habitat protection is done cooperatively by the Alaska Department of Fish & Game and Kodiak National Wildlife Refuge.
In 2001, a Citizen's Advisory Committee was established to work closely with the Alaska Department of Fish and Game and Kodiak National Wildlife Refuge to develop a management plan addressing the wide variety of issues that impact bears, including hunting, habitat, and viewing. The resulting Kodiak Archipelago Bear Conservation and Management Plan [5] was crafted over a several month period by a group of representatives from 12 diverse user groups. After hearing from a variety of experts from agencies and extensive public input, the group developed over 270 recommendations for Kodiak bear management and conservation. Most impressively, in spite of the diversity of viewpoints expressed by members of the group, all of the recommendations were by consensus.
The underlying themes of the recommendations were continued conservation of the bear population at its current level, increased education programs to teach people how to live with bears on Kodiak, and protection of bear habitat with allowances for continued human use of the Archipelago. Although the group was advisory in nature, government management agencies expressed a commitment to work to implement all of the regulations that were feasible and within their legal jurisdictions. How this maturing relationship between bears and people will evolve remains to be seen, but the future looks bright for the continuing existence of the bears of the Kodiak Islands [4]
[edit] References
- ^ Talbot, S.L., J.R. Gust, G.K. Sage, A. Fischbach, K. Amstrup, W. Leacock, and L.Van Daele, 2006, Genetic characterization of brown bears of the Kodiak Archipelago,Final report to the Kodiak National Wildlife Refuge, Kodiak Alaska, USA.
- ^ Van Daele, L.J., 2007, Population dynamics and management of brown bears on Kodiak Island, Alaska, Doctoral dissertation, University of Idaho, Moscow Idaho USA.
- ^ Email reply to request for information from Terry K. Lincoln, Director of Bismarck, ND Zoo, dated March 12, 2007
- ^ a b c Van Daele, L.J., 2003, The History of Bears on the Kodiak Archipelago. Alaska Natural History Association, Anchorage, Alaska, USA.
- ^ Alaska Department of Fish and Game, 2002, Kodiak Archipelago Bear Conservation and Management Plan, Alaska Department of Fish and Game, Anchorage, USA.
