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Post by brobear on Jun 30, 2022 10:05:23 GMT -5
It has been debated, which bear species has the longest claws. It has been claimed that the sun bear has the longest claws comparative to body size. It has been claimed that the sloth bear has the longest claws. However, a brown bear has very long claws in early spring which get worn down through use until he returns to hibernation.
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Post by brobear on Dec 1, 2022 10:24:00 GMT -5
Brown Bear www.inaturalist.org/guide_taxa/889098#:~:text=The%20paws%20of%20the%20brown The paws of the brown bear are quite large. The rear feet of adult bears have been found to typically measure 21 to 36 cm (8.3 to 14.2 in) long, while the forefeet tend to measure about 40% less in length. All four feet in average sized brown bears tend to be about 17.5 to 20 cm (6.9 to 7.9 in) in width. In large coastal or Kodiak bear males, the hindfoot may measure up to 40 cm (16 in) in length, 28.5 cm (11.2 in) in width, while outsized Kodiak bears having had confirmed measurements of up to 46 cm (18 in) along their rear foot. Brown bears are the only extant bears with a hump at the top of their shoulder, which are made entirely of muscle, this feature having developed presumably for imparting more force in digging, which is habitual during foraging for most bears of the species and also used heavily in den construction prior to hibernation.
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Post by brobear on Dec 1, 2022 22:31:14 GMT -5
Credit to King Kodiak: www.researchgate.net/publication/311948285_Bear_footprints_and_their_use_for_monitoring_and_estimating_numbers_of_brown_bears_Ursus_arctos_L_in_Bulgaria Bear footprints and their use for monitoring and estimating numbers of brown bears (Ursus arctos L.) in Bulgaria December 2016 Abstract: We present an improved table of the footprint dimensions of the Bulgarian/ Eastern European brown bear (Ursus arc-tos L.). Our results demonstrated congruence between the length of the hind paw footprint and the width of the fore one, as well as correlation between footprint size, age, and sex of the individuals. Six categories of bear fore paw and respectively hind paw footprints were identifed according to their dimensions, which are related to their body sizes (influenced also by sex and age). The table could be useful for identication of the individuals by their footprints and could be utilised in the National monitoring of the bear in Bulgaria. Examples are given to demonstrate the effective-ness of using size parameters of footprints for determination of local population numbers and structure. Quote: mature male paw width: 14.5 to 17 cm (5.71 inches). Very big old males (10+ yrs old) and more than 250 kg (records above 350 kg) 17 cm (6.69 inches) and more. 250 kg = 551.16 pounds / 350 kg = 771.62 pounds.
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Post by brobear on Dec 2, 2022 6:44:14 GMT -5
Question: is a bear paw with a width of seven inches from a huge brown bear? _____________________________________________________________
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Post by brobear on Dec 15, 2022 7:55:23 GMT -5
shaggygod.proboards.com/ First posted by Grrraaahhh.... The following interesting extract account I found awhile ago but I have not been able to find out anything more about the original source information. Maybe someone in the visiting audience is familiar with the following material: The claim that an adult grizzly bear can decapitate a moose with one swipe of its paw is an established fact. The first reported event took place in Alaska in 1895 by a Russian miner who was hiking through the wilderness. According to his account, he witnessed a moose drinking from a stream when a Grizzly bear approached from the other side. Mooses are very territorial, and they are especially known to attack anything they perceive to be a threat to their water source. The moose charged full speed across the stream, and just as it neared the bear, the bear stood up and with a quick motion swiped the moose in the side of the face. The mooses head became decapitated and flew a distance of fifteen to twenty feet. ...and quick as a spark on a fire the grizzly bear stood up and swatted the moose in the face. Why it was if you or I would swat a fly, but the impact seemed to me as loud as a gunshot. And then I was absolutely flabbergasted and discombobulated to see, a great upsplash of blood, and the mooses head detatched from the body and landed not three feet from where I was hidden, its eyes staring right at me. The bear sat down immediately and began drinking from the stream as if nothing had happened, as if it were a regular occurance to go decapitating the head of a moose. Never in my life will I forget the power of the grizzly bear... The report was met by skepticism until noted American biologist Dr. Jacob MacDonaldson observed a similar event in the spring of 1954. MacDonaldson was observing the movements of a Grizzly bear when a moose walked into the same space. The grizzly bear perceived the moose to be a threat to the cubs, and roared to scare it off. But the moose began to graze. The bear then charged the moose, but again the moose did not move. The bear then lumbered over to the moose, and with a powerful swipe of its paw, decapitated the moose. Dr. MacDonaldson later retreived the moose head an autopsy found damage consistent with that of decapitation by impact. Later studies contribute the phenomenon to both the relative weakness of a mooses upper neck and the power of a grizzly bears arm. Although a grizzly bear is very powerful, it does not have the strength to decapitate most creatures larger than a man. A moose however is peculiar in the structure of its upperneck, which is weak, and any force that puts a significant and sudden pressure on the weakest point of the neck will inevitably cause decapitation. Since 1895, there have been 15 reported cases of Moose decapitation by Grizzly, and most scientists theorize it is a natural, albeit somewhat rare, event. P.S. May the Force Be With You. This was posted back years ago (May 24, 2011) by grrraaahhh at: shaggygod.proboards.com/thread/557/general *Well, I've learned a lot during the past eleven years. No, I do not believe that a half-ton grizzly can knock the head off a moose with a paw-strike. Neither do I believe, as was often stated even in school books, that a grizzly can kill a bull bison with a paw-strike. Nevertheless, I do indeed believe that a brown bear can deliver a paw-strike with a much greater impact than either a lion or a tiger. The brown bear has stronger neck, shoulders, and arms. That shoulder hump even reinforces this already stronger upper-body strength. Also, his powerful arms have a wider range of motion than even those of a cat. See reply #280. A bear has a hard and tough paw which can withstand the repercussions of delivering a devastating paw-strike. A cat has soft paws designed for stealth.
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Post by brobear on Dec 21, 2022 1:11:50 GMT -5
Do polar bear paws hold the secret to better tire traction? www.sciencedaily.com/releases/2022/12/221219164700.htm Date: December 19, 2022 Source: University of Akron Summary: Traction is important. Humans have been continually interested in discovering how to better move across wet or frozen surfaces safely -- whether to improve shoes for walking on sidewalks or tires to maneuver the roadways. But what makes it possible for some Arctic animals to walk and run across the ice so effortlessly and gracefully without slipping and falling? Researchers took a deep dive into the paws of polar bears to find out. What the team discovered was that all bears (except sun bears) have papillae on their paw pads, but that the papillae on polar bears were taller -- up to 1.5 times. And, that the taller papillae of polar bears help to increase traction on snow relative to shorter ones. Even though polar bears have smaller paw pads compared to the other species (likely because of greater fur coverage for heat conservation), the taller papillae of polar bears compensate for their smaller paw pads, giving them a 30-50% increase in frictional shear stress.
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Post by brobear on Dec 21, 2022 1:13:21 GMT -5
Traction is important. Humans have been continually interested in discovering how to better move across wet or frozen surfaces safely -- whether to improve shoes for walking on sidewalks or tires to maneuver the roadways. But what makes it possible for some arctic animals to walk and run across the ice so effortlessly and gracefully without slipping and falling? Three researchers from The University of Akron (UA) took a deep dive into the paws of polar bears to find out. Their research was published in the November issue of the Journal of the Royal Society Interface.
Why polar bears?
The project team included Ali Dhinojwala, the H.A. Morton Professor of Polymer Science in the School of Polymer Science and Polymer Engineering, Nathaniel Orndorf, a 2022 Ph.D. graduate who is now employed as a senior material scientist at Bridgestone Americas, and Austin Garner, a 2021 Ph.D. graduate who is now an assistant professor of biology at Syracuse University. The project began during the height of the pandemic when things were on lockdown.
"We had an ongoing project for many years focused on ice; we were looking at the friction of materials and we were interested in this topic because we are in Akron and our national partners need to develop tires with a strong grip on the road in ice and snow conditions," said Dhinojwala. "Nate had an interest in how nature has adapted to this solution for snow. The example that came to his mind was polar bears -- and the research began from there." The project was very interdisciplinary, combining approaches and techniques from both biological and materials research. Orndorf and Dhinojwala are polymer scientists who integrate biology into their research, while Garner is an animal biologist who integrates materials science into his research.
The idea was to look at the paw pads of polar bears. Reviewing older literature, the team discovered that previous work studied the microstructures (papillae, the little bumps on the pad of the foot) of polar bear paws and asserted that the papillae were adaptations for improved traction on snow. The previous studies did not include other species of bear so Garner helped identify two species closely related to the polar bear (the brown bear and American black bear) and one distantly related (the sun bear) to include in the study.
"The quietness of the lab during COVID gave me the opportunity to connect with a variety of scientists and environmentalists across the country," said Orndorf. "I reached out to museums, taxidermists and many others to collect and view actual samples and replicas of bear paw pads."
Orndorf and Garner then prepared the paw pad samples from the bears and imaged them using a scanning electron microscope. The team also created 3D printouts of the structures to vary diameter and height of features. They were then tested in snow in the lab to see how they reacted to the conditions.
What the team discovered was that all bears (except sun bears) have papillae on their paw pads, but that the papillae on polar bears were taller -- up to 1.5 times. And, that the taller papillae of polar bears help to increase traction on snow relative to shorter ones. Even though polar bears have smaller paw pads compared to the other species (likely because of greater fur coverage for heat conservation), the taller papillae of polar bears compensate for their smaller paw pads, giving them a 30-50% increase in frictional shear stress. "Papillae are not unique to polar bears. Previous work [in that area] made the implicit assumption that papillae themselves are adaptations for enhanced traction on snow without studying the paw pads of other bears. It was fascinating for us to discover that the other North American bears have them as well and that the physical characteristics of the papillae are what matters for traction on snow," said Garner.
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Post by brobear on Dec 21, 2022 1:14:06 GMT -5
Impact on traction
Now that the research has been published, other scientists and manufacturers can look at its application to their specific projects.
"If you look at snow tires you will see that they do have some deeper treads, but this research could also show various ways to design them that could have a larger impact," said Dhinojwala.
But the interest isn't just for tire manufacturers. "Individuals who do high altitude climbing are interested in this research, companies that specialize in the delivery of goods in bad weather would love to have better grip, etc." he added.
The same experiments could also be performed on animals such as dogs, wolves, foxes and mountain goats to determine if specific snow/ice induced surface roughness profiles are present in different animals, [TE1] or if nature has evolved different surface roughness profiles in order to increase traction on ice and snow, and which profile has the best performance.
Building on past research
This isn't the first research conducted in the area of traction or grip at UA. As part of the Biomimicry Research Center (BRIC) at The University of Akron, and in collaboration with faculty members in the BRIC program, Dhinojwala and his team have examined gecko adhesion, spider silk, mussel adhesion, and structural colors inspired by birds and other organisms. His research is supported by National Science Foundation, Air Force Office of Scientific Research and Industries.
His team is continuing to look at ice -- how ice formation takes place, ice adhesion, etc. Research that is very helpful for the automotive and aircraft industries. His students have just begun working with NASA on a grant funded project in this area.
"It's exciting to give our students such interesting research projects to be part of," said Dhinojwala. "They are an asset to our team, and many go on to continue to be excellent research partners after they leave UA." "The Integrated Bioscience Ph.D. Program at UA provided exceptional interdisciplinary research experiences that were formative in my development as a researcher -- this collaboration was certainly one of them," said Garner. "It was a particularly unique experience for me because most of my work before this had focused on how small lizards, like geckos, attach to surfaces. So, it was an exciting and rewarding opportunity to apply my existing skills and expertise to large mammals like bears."
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Post by brobear on Dec 21, 2022 3:27:09 GMT -5
Merriam Webster: papilla noun / plural papillae.
:a small projecting body part similar to a nipple in form: A: a vascular process of connective tissue extending into and nourishing the root of a hair, feather, or developing tooth. B: any of the vascular protuberances of the dermal layer of the skin extending into the epidermal layer and often containing tactile corpuscles. C: any of the small protuberances on the upper surface of the tongue often containing taste buds.
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Post by brobear on Jan 23, 2023 15:38:42 GMT -5
How to Measure a Bear's Weight From Its Foot Size sciencing.com/measure-bears-weight-its-foot-size-10069146.html Although zookeepers may have the equipment and controlled circumstances needed to weigh a bear, in the wild you generally need to rely on estimates of weight. You can make a reasonable estimate by looking at the size of its footprints or tracks. The size of a bear's paws, and the size of the prints it leaves, allows you to make a rough estimate of the bear's size, maturity and likely weight. While in bear country, take precautions to avoid provoking a bear into attacking. Be particularly careful when mother bears are with young cubs. Measure the bear's footprint by laying your tape measure or ruler to the side of the print. Write down the length of the footprint at its longest part, from heel to toe. Also, measure the width of the print. Compare the length and width measurements. If the length and width are similar, it is likely a footprint from a bear's front paw. If the print is longer than it is wide, it is more likely a back paw print. Find out what type of bears live in the environment where you found the print. Black bears, for example, live in California and Vermont. Brown bears live in Alaska and other locations throughout North America, Europe and Asia. Compare the size of the footprint to the usual weight range of a black or brown bear. For a black bear, a front paw print 5 inches long is average, equating to an average weight of between 150 and 175 lbs. A 7-inch front print is from a bigger bear -- 300 to 400 lbs. for a black bear. An average weight for a male brown bear is 500 lbs., with a large male bear weighing up to 800 lbs. Brown bear front tracks are between 6 and 8 inches long -- a 6- to 7-inch front track would likely represent a 400 to 500-lb. bear, while an 8-inch front track would indicate a 700 to 800-lb. animal. Brown bear rear tracks are 12 to 16 inch long, with 16-inch tracks representing the heavier bears.
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Post by brobear on Jan 23, 2023 16:50:50 GMT -5
Bear Teeth: All You Need to Know! (Type, Size, Strength…) wildexplained.com/bear-teeth/ There are eight different species of bear worldwide, all in the family Ursidae. They are usually apex predators or some of the largest land animals in their respective habitats. The polar bear is the largest species, standing up to 10ft tall and weighing up to 1000lb on average (though there are bears that have been recorded at over double that weight!). The smallest bear is the Southeast Asian Sun bear, which grows to less than 55-inches and typically weighs between 55- and 140-pounds. Despite their differences, all bears share a common ancestor, which was omnivorous. As such, modern bears are generally considered omnivorous, although their diets differ from species to species. Bear teeth are typical for an omnivore and perfectly adapted to their diets. So what makes bear teeth unique? Let’s take a look! What Kind of Teeth do Bears Have? Bears are heterodonts, which means they have different teeth types that perform different jobs. By being omnivores, bear teeth are used for both meat-eating teeth and plant-eating teeth. Their teeth are made up of 12 incisors, 4 canines, 16 premolars, and 10 molars. Bears have 42 teeth in total, which is ten more than humans. Like most animals, their jaws are symmetrical, with even numbers of each type of tooth on both sides. They have the same teeth on the top and bottom jaws, apart from their molars, of which there are three pairs on the top jaw but only two on the bottom. What do Bears Eat? Every species has a different diet, but bears eat just about everything! Most of their diet is a combination of meat (such as rabbit, seal, and deer), fish, carrion, insects, fruit, nuts, seeds, leaves, shoots, and other plant matter. What do Bears Use Their Teeth for? Different teeth are used for different things. In bears, their four types of teeth are adapted to tackle both meat and plants. Incisors are small, straight, chisel-shaped teeth located in the front of the mouth. They are used for biting and are great at cutting and grabbing food. Bears have very sharp incisors, which they use to cut through meat and rake the forest floor and slice through shoots and stems. Canines only exist in meat-eating animals and are the longest teeth in the mouth. They are located behind the incisors. The canines are sharp and pointed and are mainly used to grab and kill prey. They are perfectly shaped to puncture tough hide and flesh. For this reason, they are sometimes called “fangs.” Bears use their canines to kill their prey or tear into logs to find grubs. They also use them to break open beehives to get to the honey and larvae. Premolars are found between the canines and molars and are sometimes known as “cheek teeth .”They are mainly used to chew and grind food. In meat-eaters, they are a kind of hybrid between canines and molars. They are sharper than molars but broader and flatter than canines, making them suitable for both cutting and grinding down foods like raw meat. As omnivores, bears have another exciting feature: a diastema. A diastema is essentially a gap between the premolars and the teeth at the front of the mouth, and is usually found in plant-eating animals. Bears and other plant-eaters use this gap to grab twigs and plant stems and strip leaves off branches by sliding them through the gap. Molars are broad, flat teeth at the very back of the mouth, used for grinding and crushing. Because of their position in the jaw (closest to the pivot point), these are the teeth with the most bite force behind them. Bears use their molars to grind up meat, as well as crush nuts, seeds, and bone.
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Post by brobear on Jan 23, 2023 16:52:10 GMT -5
How Big and Strong are Bear Teeth? Bear teeth range in size, depending on the species. Polar bears have the largest, at up to 2-inches, while black bears have the smallest at up to 1-inch. All bears have relatively small teeth for their size, but they are sharp, and a bear’s bite is exceptionally powerful. A polar bear’s bite is a whopping 1,200 PSI, closely followed by the grizzly at 1,100 PSI of bite force. This allows bears to break through the bark, flesh, and even bone without a problem. The power actually comes from the bear’s jaw muscles rather than its teeth. A bear’s bite force is, on average, comparable to that of a tiger and is powerful enough to crush a bowling ball! Do Bears Have Milk Teeth? Like humans and many other mammals, bears are diphyodont. This means that they grow a set of deciduous or milk teeth as babies, which fall out to be replaced by more prominent adult teeth as they grow. Bear cubs will start getting their adult teeth at around 5 months and have a complete set by about 18 months, though their canines will continue growing for several more years. If it happens to lose one, you can tell a bear’s age by its teeth. During hibernation, a dark pigment forms on the outside of the teeth, which you can count like the rings on a tree. As bears hibernate every year, the number of rings equals the number of years the bear has been alive.
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Post by brobear on Jan 23, 2023 16:52:44 GMT -5
How do Bear Teeth Differ Across Species? Polar Bear Teeth The strongest bears in the world, polar bears, live exclusively above the Arctic Circle, where relatively few plants grow. They are hypercarnivores, meaning that over 70% of their diet is meat. Their diet is mainly made up of seals, but they will eat fish, crustaceans, deer, carrion, and plants if they find them. They hunt seals through holes in the ice, waiting for them to come up to breathe. Because of this, they need to be stealthy and catch their prey in one bite. Polar bear teeth are sharper than those of other bears and curved back into the mouth, making it much harder for prey to slip away once in their jaws. Their premolars are also sharper and slimmer, more like those of other carnivores.
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Post by brobear on Jan 23, 2023 16:53:06 GMT -5
Brown Bear Teeth Brown bears are highly variable in size, depending on their region, with some growing as large as polar bears. Their diets are equally variable.
Some, such as the brown bears of Alaska, get most of their nutrition from salmon. Others, like the Yellowstone grizzlies, can get up to 90% of their calorie intake from fruit, nuts, plants, and insects.
Brown bears can and will eat anything from acorns to elk and are efficient at hunting and gathering.
Brown bear teeth reflect their dietary versatility and are similar to some other bear species. They are generally more robust and larger.
Because they eat meat, they have sharp, curved incisors, like the polar bear.
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Post by brobear on Jan 23, 2023 16:53:25 GMT -5
Black Bear Teeth The black bear’s diet consists of over 75% plant matter. The little they get from animals comes from insects and occasionally fish and deer fawns.
As they are not very predatory, their teeth are not as sharp as those of their more carnivorous cousins, and their incisors are straighter.
Black bear teeth are undoubtedly sharp and large enough to catch prey and slice meat but are more often used to cut and grip plants or crush nuts and seeds.
They are known to have a particular fondness for honey and will use their long canines and sharp claws to tear apart the hive.
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Post by brobear on Jan 23, 2023 16:54:03 GMT -5
Sun Bear Teeth The sun bear is the smallest bear species and feeds mainly on honey, insects, fruit, and plants, though they will sometimes supplement their diet with small reptiles or eggs. The sun bear has an exceptionally long tongue, which it uses to poke into termite mounds and suck up the insects. It also has powerful claws that break apart insect nests or strip away bark from trees. One would assume this means its teeth are comparatively small, but for some reason, they are huge for the bear’s size.
The sun bear has unusually long canines and very strong jaws, usually associated with more predatory animals.
Experts suggest this may be to help it break open hardwood trees to get to the grubs inside, but so far, there isn’t a clear explanation for their impressive teeth.
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Post by brobear on Jan 23, 2023 16:54:46 GMT -5
Spectacled Bear Teeth The spectacled bear is a primarily herbivorous species native to South America. Only up to 5% of their diet is meat, so these bears are not considered predatory.
They eat all different kinds of plant matter but specialize in pineapples, sugarcane, tree bark, and palm nuts, which are too harsh for most animals to get into. For this reason, they have firm jaw muscles and teeth that are better adapted for grinding tough plants than other bears.
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Post by brobear on Jan 23, 2023 16:55:48 GMT -5
Giant Panda Teeth The giant panda is at the other end of the spectrum from the polar bear, as it is almost entirely herbivorous. Despite this, it retains many characteristics from its meat-eating ancestors, such as large canines and a short digestive tract.
As such, it is highly specialized at eating one thing in particular: bamboo shoots. Because its carnivore-like digestive tract is not well adapted to breaking down vegetable matter, pandas do most of the work in their mouths.
Pandas have massive jaw muscles – giving them their characteristically round faces – and large molars, both designed to grind down the huge amounts of bamboo they need to eat every day. In Summary Because of the challenges global warming is creating for animals worldwide, many are faced with adaptation or extinction. Polar bears are particularly precarious, and their numbers are dwindling rapidly. Many are forced to move south into brown bear territory, searching for food. One might think this creates conflict, and indeed it does, but it also appears to be creating hybrids. Once believed to be cryptids, polar/grizzly hybrids – otherwise known as “pizzlies” or “grolars” – are starting to occupy a niche neither of their parents is as well adapted to.
They share characteristics with both polar and brown bears, including their teeth. Maybe we will see the rise of a new species in the not-so-distant future, with its very own set of unique teeth!
Thank you for reading. Hopefully, this article on bear teeth was informative and fun to read.
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Post by brobear on Jan 27, 2023 5:42:00 GMT -5
Limbs: seaworld.org/animals/all-about/polar-bear/characteristics/ The hind limbs are longer than the forelimbs. This makes the large, muscular hind end stand higher than the shoulders. Feet are five-toed paws. Polar bears have large paws compared to body size, reaching 30 cm (12 in.) in diameter. The large paws of a polar bear act like snowshoes, spreading out the bear's weight as it moves over ice and snow. The forepaws are round and partially webbed. The hind paws are elongated. Each toe has a thick, curved, non-retractile claw. The claws are used for grasping prey and for traction when running or climbing on ice. The sole of a polar bear's foot has thick, black pads covered with small, soft papillae (dermal bumps). The papillae create friction between the foot and ice to prevent slipping. Long hairs growing between pads and toes also help prevent slipping.
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Post by brobear on Jan 27, 2023 5:43:25 GMT -5
Polar Bear Facts bear.org/polar-bear-facts/ Feet: Polar bears have large feet, which help propel them through the water as they swim. When they are on the ice or snow their feet act as snowshoes by spreading out their weight and keeping the bears from breaking through (Stirling and Guravich 1990, p 24). Their feet are flatter than those of other bears and are useful for shoveling snow when building dens (Brown 1993, p 73). The pads of the polar bear are covered with small papillae, which increase friction between the foot and the ice. There are also small depressions in the pad that function as little suction cups and increase the grip of the polar bear’s paws on the ice when it runs (Stirling and Guravich 1990, p 25). Tracks: A polar bears forepaw is approximately 5 ¾ inches long and 9 inches wide while the hindpaw usually measures 13 inches long and 9 inches wide. The toes form an arc similar to a black bear’s track. A polar bear’s track is generally only visible in soft snow or mud and may show fringed edges due to the hair on the paw (Brown 1993, p 76). The bottom of the paw is completely covered with fur. The claws are black, short and stocky and are usually not visible in the track (Stirling and Guravich 1990, p 39).
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