"Not As Small As They Look",1,34700034.bmp,c,009.wav
A 350-pound (157-kilogram) black bear may seem surprisingly small when viewed from a distance; indeed, so may a grizzly bear weighing twice as much. Upon first seeing bears in the wild, people are often surprised by animals that appear smaller than expected. This is merely because bears are round-bodied, low-slung creatures whose legs are short by comparison with torso size, and the thickness of the legs adds to the illusion of squatness.
That same 350-pound bear is considerably taller than an average man when it rises up on its hind legs to sniff for food or alien scent, listen for any intrusive sounds, and scan its surroundings for the sight of anything that needs to be avoided, attacked, or eaten. Bears have the reputation of being nearsighted, chiefly because they seem to ignore stationary objects or creatures unless fairly close, relying on scent and sound more than on vision. But anyone in bear country will do well to remember that experiments have proved bears to have fairly keen eyes -- and nothing escapes their hearing and \Polfactory\p senses. As for the grizzly, which attains twice the weight of the black bear, when it rises on its hind legs it may tower nine feet (2.73 meters) tall, and a mature male Alaskan brown bear is often considerably larger.
\BDescription:\b Brown bears have a broad head, a heavy body and strong muscular legs. Brown bears have a large muscular lump over their shoulders which adds digging and striking power in their \Pforelegs\p.
\BPhoto:\b Gerry Ellis - Ellis Nature Photography
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"Wide Range of Body Weights and Sizes",2,34700004.bmp,c,010.wav
The various species of bears encompass a surprisingly wide range of body weights and sizes. At maturity, the sun bear of the Southeast Asian tropics quite often weighs no more than 80 pounds (36 kilograms) -- great size being of no particular advantage in a hot climate. With obvious exceptions, such as the elephant, animals near the equator tend to be smaller than those in the north -- especially those belonging to the same family. This is because a large animal conserves heat more efficiently than a small one. Alaskan brown bears (or coastal grizzlies, as they are also known) generally attain a weight between 800 and 1,200 pounds (360 to 540 kilograms) at eight or nine years of age, and one Kodiak brown bear was reported to weigh 1,656 pounds (745 kilograms).
\BDescription:\b Malayan sun bears are the smallest of the bear species.
\BPhoto:\b Gerry Ellis - Ellis Nature Photography
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"World's Largest Carnivorous Mammal",3,27040016.bmp,d,011.wav
Male polar bears vie with Alaskan browns for the rank of world's largest \Pcarnivorous\p mammals. At maturity, females generally weigh well over 700 pounds (315 kilograms), and males generally weigh about 1,000 (450 kilograms). The largest specimen ever recorded weighed 2,210 pounds (990 kilograms) -- around a ton!
\BDescription:\b Adult male polar bears have been known to reach as tall as 350 centimeters (11.5 feet) measured from the tip of the nose to the tip of the tail.
\BPhoto:\b Todtri Productions Limited
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"World's Largest Carnivorous Mammal - (2)",4,0,c,polrhair.avi
The polar bear has unparalleled resistance to cold, resulting from several anatomical marvels. Sometimes the fur is stained, and in summer may turn yellowish from oxidation caused by the sun, but normally the coat appears to be ivory or snow white because it reflects and scatters all visible rays of the spectrum. Actually, the individual outer hairs -- guard hairs -- are not white but clear and hollow. Many mammals have hollow guard hairs, an effective form of insulation, but a polar bear's are different.
Its coat releases almost no heat -- not even enough for the animals to be censured by aerial infrared photography. Ultraviolet photography works, however, because snow reflects ultraviolet radiation while the fur absorbs it, creating a contrast. The clear, hollow hairs trap ultraviolet radiation and conduct it to the bear's skin, which is as black as the animal's nose and lips, and absorbs the heat. This radiation is caught from any direction and, for reasons not yet understood, the ultraviolet energy flows only inward to the skin, with almost none escaping. Astonishingly, this system is ninety-five percent more efficient in converting rays to usable heat.
But the air temperature may be well below zero, and a polar bear can still swim 50 miles (80 kilometers) through \Parctic\p water without resting -- and without much exposure to sun -- so the heat conveyor alone would not suffice, nor would the woolly under coat. Beneath the skin is a layer of fat, comparable to the blubber of marine mammals, which may be over 4 inches (10 centimeters) thick when winter arrives. It provides both insulation and buoyancy for swimming. Finally, the circulatory system incorporates a "countercurrent" like a seal's to cool the blood as it flows toward the body's surface and warm it on the return flow -- an "automatic heat engine," as one research described it.
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"Food and Foraging",5,0,c,bearfsh1.avi
Although a polar bear will eat whatever meat it finds, including anything from gulls to whale \Pcarcasses\p or other such \Pcarrion\p, seals are its chief \Pprey\p and it hunts them with uncanny efficiency. Brown bears are far more \Pomnivorous\p, but the main reason the Alaskan browns attain such gigantic proportions is the easy availability of protein in the form of salmon -- seemingly countless salmon struggling their way up Alaska's shallow streams during the spawning runs.
A brown bear will also dig out hibernating \Pmarmots\p, excavating huge pits in the \Ptundra\p with claws and feet powerful enough to demolish \Ppermafrost\p, and it will feast on \Pcarrion\p or any live \Pprey\p it manages to catch. All the same, even the largest Alaskan brown bear generally devours considerably more vegetation than meat in the course of a year.
Thus these strange animals can be accurately described not only as the world's largest mammalian carnivores but also as the least \Pcarnivorous\p of carnivores.
\BDescription:\b This North American brown bear has found some nutritious berries to feed on. Seventy-five per cent of the brown bear's diet is said to be vegetation.
