Yet another myth about polar bears is that they cover their nose while hunting seals. It just doesn’t stand to logic for the statement isn’t only bizarre—it’s highly contradictory. Why would a polar bear cover its nose when it relies on its remarkable sense of smell for hunting? No wonder Dr. Ian Stirling, a leading polar bear scientist, used telescopes to actually observe polar bears in the Canadian High Arctic as much as 24 hours a day. He never reported anything like that. Let’s see how do polar bears cover their nose during hunting.
Do Polar Bears Cover their Nose?
Let’s say, for the sake of argument, polar bears really cover their nose. If that is so, then how can polar bears possibly walk or stalk on the remaining three legs when one of their paws covers their nose for an extended period.
Most, if not all, polar bear hunts cover as much as 50 – 200 meters so polar bears just cannot afford to do that. In fact, they can either stand still whilst holding one of their paws over their nose or just go after the prey. Many researchers and scientists have quite deeply studied the polar bear hunting behavior. None of them came up with facts such as these.
Polar bears (Ursus maritimus) are as deadly and powerful as they probably look! But their looks can only tell us about their size more than anything else. If we deeply study the characteristics and physical features of a polar bear then perhaps it can reflect on its ability to stand out in the entire animal kingdom. Ice bears are extremely strong and well-developed and they have long dominated their ecological niche in the Arctic’s frigid habitat. Very few mammals enjoy the same status. Polar bear’s neck and skull are so powerful that it can pull animal nearly the size of its own. Let’s take a look at the adaptive features of polar bear.
Polar Bear Physical Characteristics
Polar Bear Nose and Snout
Polar bears are primarily known for their acute sense of smell. Thanks to its sharp nose with the help of which the bear is able to smell its primary prey (ringed seal) hidden 2 feet under the snow. This is quite remarkable adaptive feature because it allows the animal to sense the wind direction and then follow the smell. They are thought to detect the animal’s movement from 1.6 km away. Even the thick snow cannot prevent the seal from exposing itself to the arctic’s predator. If the seal is exposed on an open ice the bear senses it from as far a distance as 20 kilometers.
Polar bears possess the longest snout of all Ursids and there is good reason for this adaptive feature. Arctic bears must hunt seals to stay alive but seals remain in water. Bears while standing on the ice float attempts to reach the prey by smashing the ice. The long snout helps her to get to the prey with minimum resistance. The snout also performs another function in that it serves as a tool to make cool air warm so that the air gets moistened before reaching the lungs.
Polar bears seem to have dark black eyes but they are fairly smaller as compared to the animal’s body size. The small size of polar bear’s eyes possibly reduces the risk of snow blindness. There is a nictitating membrane that surrounds the eyes so that the bear doesn’t get hit directly by the sunlight. Polar bears can also identify colors but the vision is quite limited.
There are total 42 teeth inside polar bear’s mouth but all of them are of different sizes. The canines are the largest, sharpest, and the most powerful of all teeth. Bears use their canines to tear the soft parts of the flesh. Incisors are the smallest and deciduous teeth. Polar bears are capable to rip the hardest flesh with their penetrating sharp teeth.
The polar bear’s ears are rounded but short. This is probably an adaptation to enable the bear to swim for hours and even days. If the bear had long ears the water would have entered the ear canal and damaged the ear drum. This has been a quite useful trait because ice bears spend more than half of their lives under water.
Polar bears have got quite many special feature to deal with the Arctic sea ice. Polar bear physical features. Photo by World Wildlife Fund.
Unlike tigers, polar bears have non-retractable claws. Bears walk with claws exposed all the time and thus providing a firm grip on the icy surface. Arctic bears can also hold prey with their claws which gives an edge to other predators.
No wonder polar bears are covered with a dense coat jacket which prevents the animal from getting hit by the extreme cold. This is the only way to survive the harsh environment of the tundra. The polar bear hair is divided into two classes—external guard hairs and an insulating underfur. The guard hairs are little silky, transparent and hollow. Bears have 10,000 hairs per square inch. Another trait is that polar bear hairs are water resistant so that water doesn’t stick to the coat.
Polar bear’s hair lacks pigment which means it adopts the color of the light that shines on it. During sunset or sunrise the bear becomes yellowish-orange. The molting begins in spring and ends in late summer. During these days many bears would appear to have black spots on their body. This is because black skin becomes visible where hairs disappear.
All bears including polar bears have short tails—possibly one of the shortest tails in carnivorous land mammals. Polar bear’s tail is even shorter as compared to other bear species probably because it prevents the considerable heat loss from the tail.
White bears have exceptionally large and wide paws as compared to their overall body size. The paws are meant to distribute the bear’s weight over the surface area so that she can move efficiently on the snow.
There are papillae that cover the pads of the polar bear’s feet. The papillae are also called dermal bumps. They prevent the animal from slipping while gripping firmly on the snow. Polar bears have partially webbed feet so that they can swim with ease.
Image Courtesy: Churchill Wild
Polar Bear Special Features
Polar Bear Sixth Sense—Direction
Polar bears are blessed with amazing ability to navigate the Arctic Circleusing their extraordinary sense of direction. They are quite expert in finding way back home even in absolute darkness which can last for as long half a year in the Arctic. Scientists have not been able to uncover the real cause of this skill. It is reasonable to assume that polar bears possess a special compass (within) that coincides with the earth’s magnetic field to show them their way.
Polar Bear Stature
Unique in polar bear’s stature is that its body is narrowly built with an elongated neck and face. Looking from sideways polar bears appears to be slanted from the front. This is due to the fact that their front legs are shorter than their hind legs. The slanting body assists the animal to get to the breathing hole.
Ice bears have an outstanding stomach in that it can process meat with the highest contents of fats. There would hardly be any animal in the entire kingdom that digests such fats. Juveniles rely on seal’s meat whereas adults mostly consume the blubber.
Polar Bear Sexual Dimorphism
White bears are sexually dimorphic mammals. Adult females are 2 – 3 times smaller than the adult males. Except for the size no other major difference is thought to be observed between two sexes.
Polar Bear Blubber
Ice bears are insulated with the 4-inches-thick layer of blubber. Half of the bear’s weight consists of its blubber. The blubber together with the bear’s fur serves as thick jacket and the jacket makes the bear to afloat whilst swimming. The blubber also performs a useful function of energy storage. During warmer months bears rely on these available fats since the seal hunting becomes impossible. When bears want to consume reserve fats the oxygen is mixed with the fat to give metabolic water and carbon dioxide. Freshwater is a rare commodity in the Arctic Circle but polar bears know how to deal with the water scarcity.
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POLAR BEAR ANATOMY: The average heart beat rate in adult polar bears is 60 to 90 bpm however in cubs the rate reaches high up to 130 beats per minute. The high bpm in cubs is mainly because of their activity level.
POLAR BEAR SKULL: The polar bear’s skull is a typical of any other land carnivores. Bears unlike other carnivores have relatively deep and flattened mandibular fossa.
POLAR BEAR ORGANS: The polar bear’s heart is slightly larger than the human’s heart but it is less than one-third of the hippo’s heart. The four-chambered bear’s heart consists of left and right ventricles as well as left and right auricles.
Polar bear eyes are set in such a way that the animal can look forward with a binocular vision. However the bear’s eyes also enable her to have a pretty good vision of the sideways. Polar bear’s eyes are one of the least understood physical features. Scientists are carrying out research on the anatomy of eyes but so far with little success. Much of the information is speculated as to how far a polar bear can see on the sea ice.
Scientists from Russia report that polar bears have poor eyesight. Certain biologists however believe that white bears have been underestimated in sight. They are able to see things, animals or even humans from long way off. It is just that we (scientists) couldn’t come up with the appropriate scientific explanations.
How Far Can a Polar Bear See? – Polar Bear Vision
The spherical-shaped polar bear’s eye allows it to visualize things on land but not underwater. In marine mammals the eye lens is usually spherical because it provides a shortest focal length for a given diameter. However in polar bears the lens doesn’t seem to provide any such acute vision underwater. The white bear’s eye possesses a circular pupil.
Polar bears have got the ability to see animals under low-light conditions which helps the bear to hunt at dusk. The iris in the eye is brown and it doesn’t appear to change its color.
Can Polar Bears See Color?
Polar bears are dichromats meaning they are able to match any color they see with a mixture of only two colors. This particular trait is extremely rare in humans. Humans typically possess trichromatic color vision. Polar bears are known to see colors though not in a way humans do. Perhaps thanks to nature that white bear’s eyes are small which makes it less vulnerable to snow blindness. The greater is the eyes the greater is the risk of snow blindness.
Andrew E. Derocher writes in his book, Polar Bears: A Complete Guide to their Biology and Behavior“I was wearing a bright fluorescent orange jacket…..One rainy day when I approached 8-month-old cubs (their mother was drugged), I noted that they were greatly agitated and bolted when I approached. Sensing that something was wrong, I removed my new jacket. I could now approach the cubs.”
Polar bears can see long and short cones. The short-wave cones are thought to be rather susceptible to blue light whereas long cones to yellow light. There is a middle cone that is prone to the green light. Humans possess the middle cone which is what makes them trichromatic. It means that polar bears can’t see green light. However it’s logical to assume that polar bears don’t need to see green light on the icy habitat. Their eyes are equipped with rods which allow them to see things at night. This is a highly useful trait in the long nights of the Arctic.
Although polar bear do not typically rely on their vision they can see reasonably well perhaps not as bad as one might anticipated. How far can a polar bear see? Photo by Eyes On You Safaris.
Why Can’t Polar Bears Go Snow Blind?
The visible portion of the eye is small which is good because there can be 24-hour sunlight with continuous snow blowing in the Arctic Ocean. If humans were to spend that much time on the sea ice they would probably go blind in just few hours.
Snow blindness occurs when the ultraviolet light reflects from the snow to the eye surface causes the latter to burn. No wonder it is highly painful but polar bears are oblivious of it. Scientists have yet to figure out the scientific answer.
Other animals such as Ground Squirrels can also avoid snow blindness but they have yellow pigment in their cornea which prevents the squirrels from ultraviolet reflection. The yellow pigment serves as sunglasses. There is no such pigment in the polar bear’s cornea. Biologists maintain that white bear’s eye must have something that acts as a protector but they don’t know what it is. However there’s one thing they know (for sure) that polar bears do not suffer from snow blindness.
Polar bears have probably the best sense of smell throughout the entire animal kingdom. Dogs can detect any object hidden 40 feet underground if they stand right at the top. Polar bears, on the other hand, are able to smell seals 3 feet underneath the ice even if they stand at about 5,249 feet from the source. That is why they rely more on their smelling sense than on hearing or sight. The polar bears hearing sense is nearly equal to that of a normal human.
How Far Can a Polar Bear Smell?
Polar bears use their keen sense of smell not only to find seals but also to pick out the smell of their counterparts. While navigating through the arctic habitats, white bears will sniff on each step. This shows how much alert the bears are not only to the prey but also to any possible threat. This is quite handy during mating season when male bears must find females.
Yes they probably do! Thanks to their remarkable sense of smell polar bears can afford to wait thousands of feet from the prey—letting herself to go unnoticed. The most popular hunting method is still hunting in which the bear crouches with light steps while approaching the seal breathing hole. She can wait for hours in order to allow the seal to swim near the surface. When the seal exhales the polar bear smells it and reaches for the kill.
A polar bear can detect the scent of its prey more than a mile away. How far can a polar bear smell its prey? Photo by: Vladimir Melnik/Shutterstock
Polar Bears Olfactory Nerves
The study of polar bear’s skull shows that the foramen (the opening or passage in the bone) is linked with 12 cranial nerves. The cribriform plate (a sieve-like structure between the anterior cranial fossa and the nasal cavity) supports the olfactory nerves. This is quite common in all animals which have acute smelling sense.
The cranial nerve typically finds its way via optic foramen and punctures the orbitosphenoid bone. The orbital bone lies at the anterior lacerate foramen. The foramen rotundum together with the foramen ovale are thought to puncture alisphenoid bone. Scientists have recently come up with the discovery of another cranial nerve which lies at the olfactory nerve. These nerves assist the bear to locate prey which may be a mile away.
Polar Bears can Smell Humans
While polar bears do not normally eat humans they do however attack if they find one on their way. The olfactory signals help the bear to detect the human sweat. Sometimes it so happens that a hungry polar bear is navigating through the arctic and suddenly she finds hikers or photographers who have set a camp. All of a sudden she finds you as a prey. Furthermore the smell of a carcass can bring the bear near you so beware not to set up a camp near carcass.
Polar bears (Ursus maritimus) communicate with each other not only through words but also by actions. They speak to one another just like we humans do. One of their body postures is known as head wagging which is a sign of excitement and suggests that the bear wants to play. Polar bears also communicate through smell, sight, and touch. They will utter growling call or grind their teeth when they are offended. Polar bear cubs are likely to smack their lips which indicate that they are scared.
How Do Polar Bears Communicate?
Adult males often fight in playing and they do so when one of the individuals advances towards the other by lowering down its head; not looking into other’s eyes, with mouth closed and front paws to the side. The first contact is typically made by mouthing and touching the other’s neck. Minutes later they both stand only on hind legs which shows they are ready to play-fight. During play-fight one polar bear will push the other with her forepaws.
How Do Female Polar Bears Communicate with her Cubs?
A female polar bear is known to communicate with her cubs by touching her muzzle, body, and paws. When mother is angry she just touches cubs with her forepaws or utter a low growling sound but when she wants to show affection she might use her muzzle against the cub’s muzzle. In order to give comforts to the cubs the mother mostly nuzzles her snout. When she wants to send warning or threat signal to her cubs then she utters chuffing sound. The cubs respond to her call and get as close to her as possible.
When polar bears growl it means that they are extremely angry. A deep growling may also suggest the mother bear is protecting her food—she is just telling others to stay away. If an intruder doesn’t listen to her warning then she might charge with her heads down and ears back. However apart from that mother usually avoid getting into conflict with adult males and they only do so when provoked. She would also stay downwind of aggressive bears so that it may not smell her.
