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The Bear Facts - General bear information
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Anatomy and Behavior

What an animal does, as well as what it looks like, says a lot. These nuggets of information may help explain the variety of lifestyles within a family of just eight species.
And No Pockets for a Compass
Bears may travel incredible distances during their lives. Whether roaming the outer edges of their home ranges as food sources go in and out of season, finding a mate on seemingly endless ice floes, or traveling to salmon spawning grounds at just the right time, bears travel throughout their lives. How they do this has not been thoroughly investigated. One suggested method is simply by incredible memory. For example, cubs that follow their mother 20 miles to an oak stand to eat acorns one fall returned there to feed three and five years later. However this does not explain how bears, transported hundreds of miles from their home range because of "nuisance" behavior, find their way back to their original location. Polar bears have even more of a challenge, finding their way in an endlessly white world of snow and ice. And yet they do: researchers have tracked polar bears traveling in straight lines across an ever-changing, ever-moving icepack, heading for some precise destination point. The polar bears even remain on course when the ice beneath them is moving.
One theory to explain this amazing ability suggests that bears may use the Earth's magnetic field and extrapolate its position from local magnetic gradients. Some believe the bear's sense of smell is what guides it. Whatever navigation methods bears do use, they have a distance limit. Bears released 198 miles away from their range, quickly returned home, but bears that were transported 870 miles away moved in random directions after release.
When Bears Sign In
Just as humans paint their houses different colors and put street numbers on their mailboxes, bears seem to need to proclaim their territory too. Black bears "sign in" by biting or clawing trees. These marks have been found along woodland trails, with the marks clearly visible from the trail some
5 - 7 feet high on tree trunks. Males tend to mark trees before and during breeding season and females tend to make mark at the end of summer and fall. No one is really sure why bears mark trees but different theories see it as a bear's way of staking out territorial boundaries, a way to communicate with other rarely-seen bears or as an aid in navigation.
Other species of bears also use various marking techniques in their territories. Giant pandas have been known to claw trees, urinate and rub their anal regions on trees to leave scent marks for other pandas. Sun bears regularly leave obvious claw marks in trees along rainforest trees. Sloth bears make grooves in tree trunks and then rub vigorously against them, adding scent to the visual markings.
The exact reason for any of these marks is not clear, but they undoubtedly serve an important social function in the complex lives of these usually solitary animals.
Bear Sounds
Since bears are usually not found in social groups, their vocalizations are rare. The obvious exception would be a mother bear with cubs. Cubs need to communicate, often quite loudly, through cries, whines, and whimpers when distressed, hissing when frightened and a loud humming sound when contentedly nursing or drowsing. Mother bears also have a range of sounds from snorts that call her cubs to follow, scolding growls to correct youthful behavior and loud woofs that send cubs scrambling up the nearest tree to safety. In general, bears that live in thickly forested, visually restricted environments as do black bears, sun bears, sloth bears, Andean bears and giant pandas tend to be much more vocal than bears that live in open territory such as brown bears and polar bears. In open territory, visual signals send the message, not vocalizations.

Brown bears (Ursus arctos)
In Bear Feet
One of the reasons people have always been fascinated by bears is that they can stand upright and even walk for short periods, just like we do. That's because bears are plantigrade, that is, they walk by pressing their heels against the ground. Their ankle joints are positioned just above the ground. Bears usually move about on all fours but often stand up on their hind legs to have a better look around. Bears can run incredibly fast despite their bulky appearance.
The bear's broad paws, massive limbs, plantigrade hindfeet and short back provide strength and mobility of limb movement. The relatively short limbs of bears are capable of producing large forces over a great range of motion. The broad paws support the bear’s body especially when balancing on their hindfeet. Bear paws also have non-retractile claws.
Each of the eight bear species lives in different types of habitats and their feet all have special adaptations for their different environments. For instance:
— The giant panda has modified a wrist bone that forms a sixth digit, which looks a lot like our thumb,    that is useful in holding onto the bamboo stalks the panda eats.
— The polar bear's front feet are webbed like a duck's, making it the most powerful swimming bear.    Often found miles out to sea in the cold arctic waters, polar bears are considered marine mammals     just like seals and walruses. The soles of a polar bear’s feet also have small papillae and vacuoles     like suction cups so they don't slip on the ice.
—The Andean, black and sun bears have curved, hook-like claws for climbing trees.
—The brown bear has long, straight claws for digging up vegetation.
—The sloth bear has large, curved claws to open nests of insect prey.
Sharp Teeth, Sweet Tooth
Most bears are just like people, wanting a diet composed of many different types of food. That's called being omnivorous and American black bears, brown bears, Andean bears, Asian black bears and sun bears are all omnivores. They'll eat grubs, berries and herbaceous plants in huge quantities. These bears will also eat squirrels, mice, fish and a large bear may even kill a deer.
Some bears are more specialized feeders, like the polar bear, living on the cold arctic ice, is almost exclusively a meat eater or carnivore. But on those few rare occasions when a polar bear can find a berry patch in bloom, then every one of those berries will be eaten and enjoyed. The giant panda, on the other hand, is almost entirely herbivorous, living on a diet of 30 types of bamboo and only occasionally eating other plants and very little meat. The Sloth Bear lives almost exclusively on a diet of termites (as seen to left) and is therefore considered an insectivore. Its specially adapted muzzle molds to form a tube through which the bear sucks up insects from their nests, making a sound that can be heard over 300 feet away.
Everyone knows the childhood story of Winnie the Pooh and his honey jar and it's a story well based in fact. Real bears like honey so much they will break open bee-hives with their heavy paws, often being painfully stung on their muzzle many times over just to satisfy their sweet tooth.
Sniffing, Stalking and "Cache-ing" In
Different bear species use different strategies to find and catch their meals but all bears rely upon their powerful sense of smell to help them locate a tasty morsel. Whether its a ripe berry patch, a dripping honey comb or a seal sunning itself on the ice, bears rely on their noses first to tell them it's dinner time.
After a polar bear's nose indicates a nearby seal, the great animal insures its meal by stalking, that is, the bear follows its prey very carefully so that the seal does not sense its presence. Polar bears have to be very skillful to catch a seal lying a few feet from the water. The bear's snow white coat acts as camouflage and the large animal can move in absolute silence as their feet are huge and padded. They are also capable of lying motionless for several hours, waiting for just the right moment to attack. The polar bear will then kill with a single powerful blow from a front paw or a swift bite to the neck.
All hunting bears approach their prey from downwind, ensuring that their own scent is carried away from the unsuspecting animal. Some bears, such as the black bears, rely strongly on their sense of smell to find moose calves and white-tailed deer fawns. Much larger brown bears have been reported killing 3 or 4 adult moose per year.
Polar bears and brown bears, the two most carnivorous species, have different feeding methods. Polar bears feed only once on a seal, getting the maximum amount of calories and then leaving the remains for scavengers to pick over. Brown bears prefer to revisit their food source over a period of a few days and so they hide their kill by covering it with dirt and leaves and return to feed on it later. This hidden food is called a cache and allows the bear time to get the maximum amount of benefit from a large kill.
When is a Black Bear Blue?
Black bears should be black, that just makes sense, and most of them are. But they can also be dark brown, cinnamon brown, light tan, steel-blue and even white. Some "black" bears may even change color during their life. Young bears born with brown fur have grow up to be black, and some born with black fur grew up to have rich brown fur. "Blue" black bears are found in Alaska and Canada and are often called the "Glacier Bear". Blue bears actually have silver tipped fur, with a rich blue-black undercoat. All of these black bears, whether black, brown or blue all have tan muzzles.
The most unusual black bear is the white Kermode bear, found on a few islands off the coast of Canada and extremely rare. They are known as the "Spirit Bear" and were revered by the native peoples of the area as being a mystical creature. Interestingly, a Kermode female can give birth to either black, brown or white cubs.
Who's Been Sleeping in My Bed?
Bears usually construct day beds during spring and summer. Tropical bears such as the Andean bear may use day beds all year round as well as for birthing beds. Day beds are found near food sources and they are sometimes elevated to get a good view of the surrounding area. A day bed can be used for a long or short period of resting and they are often used after a heavy meal. Different bear species prefer certain day beds:
The polar bear digs 'dens' or pits in the snow ice or dirt lined with moss and lichens. Females and their cubs usually choose areas that are as high as possible so the they can detect any possible dangers.
The American black bear sleeps stretched out in trees, or if it sleeps on the ground it prefers grassy areas or areas covered with conifer needles.
The brown bear, too large for most trees, sleeps on the ground; preferring areas covered with grass or conifer needles. Brown bears have also been known to dig shallow pits in the soil or snow and line them with leaves for extra insulation.
The Andean bear creates a nest of broken branches in a tree. It rests sitting with its forelegs in front of its chest.
The giant panda prefers to sleep at the bottom of trees, under stumps, under overhanging rocks, in hollow trees, in rock caves or on a bed of bamboo sticks.
The Asiatic black bear likes to sleep in trees in a sitting position at least 15 ft above the ground. It may also sleep in a nest of branches on the ground.
The sloth bear makes its nest in a cave during the rainy season or in a tree during the dry season.
The sun bear sleeps in a nest of broken branches high up in a tree. It rests lying on its belly.
Getting Ready for Bed
Bears that live where the temperature drops every winter causing food to become scarce, pass the time away in a deep winter sleep. It's not real hibernation because their body temperature, respiration and metabolic rate barely fall - they awaken easily but can sleep for as long as a month in the same position if they are not disturbed. The bears' winter sleep and the preparation for it is an adaptation to life in places where winter conditions might otherwise threaten their survival. Most bears take their long winter nap in a cave, hollow tree, shelter of brush pile or they may even dig a den. They often line their sleeping place with dried leaves and grasses for added insulation against the harsh winter temperatures.
Once snuggled in their winter den a bear may remain inside for up to 2 - 7 months without eating, drinking, urinating or defecating. Their unique metabolic system allows them to live off their fat reserves and reprocess internal waste products so they can keep sleeping. Just prior to hibernation bears consume as much as possible, up to 20,000 calories (the equivalent of 42 hamburgers) per day to fatten up for their long fast. Female bears will give birth and nurse their cubs during this time of extended fasting, so building up fat reserves is extremely important. During hibernation a bear will burn up about 4,000 calories per day.
Tropical bears that can feed throughout the year, such sun bears, sloth bears and Andean bears and bears in zoos that are fed year-round, do not hibernate.