Walruses, Walrus Pictures, Walrus Facts - National Geographic Size relative to a 6-ft (2-m) man Please add a "relative" entry to your dictionary. The mustached and long-tusked walrus is most often found near the Arctic Circle, lying on the ice with hundreds of companions. These marine mammals are extremely sociable, prone to loudly bellowing and snorting at one another, but are aggressive during mating season. With wrinkled brown and pink hides, walruses are distinguished by their long white tusks, grizzly whiskers, flat flipper, and bodies full of blubber. Walruses use their iconic long tusks for a variety of reasons, each of which makes their lives in the Arctic a bit easier. They use them to haul their enormous bodies out of frigid waters, thus their "tooth-walking" label, and to break breathing holes into ice from below. Their tusks, which are found on both males and females, can extend to about three feet (one meter), and are, in fact, large canine teeth, which grow throughout their lives.

Male walruses, or bulls, also employ their tusks aggressively to maintain territory and, during mating season, to protect their harems of females, or cows. The walrus' other characteristic features are equally useful. As their favorite meals, particularly shellfish, are found near the dark ocean floor, walruses use their extremely sensitive whiskers, called mustacial vibrissae, as detection devices. Their blubbery bodies allow them to live comfortably in the Arctic region—walruses are capable of slowing their heartbeats in order to withstand the polar temperatures of the surrounding waters. The two subspecies of walrus are divided geographically. Atlantic walruses inhabit coastal areas from northeastern Canada to Greenland, while Pacific walruses inhabit the northern seas off Russia and Alaska, migrating seasonally from their southern range in the Bering Sea—where they are found on the pack ice in winter—to the Chukchi Sea. Female Pacific walruses give birth to calves during the spring migration north. Only Native Americans are currently allowed to hunt walruses, as the species' survival was threatened by past overhunting.

Their tusks, oil, skin, and meat were so sought after in the 18th and 19th centuries that the walrus was hunted to extinction in the Gulf of St. Lawrence and around Sable Island, off the coast of Nova Scotia. The Walrus The walrus is a distinctive marine mammal with its tusks. The walrus was named for �toothwalker� because it often uses its distinctive tusks to help itself drag its body across the ice or land. Formally called Odobenus rosmarus, most scientists consider the walrus to consist of two subspecies � the Pacific walrus (Odobenus rosmarus divergens) and the Atlantic walrus (Odobenus rosmarus rosmarus). The Pacific walrus is larger, darker and much more numerous. Resting walrus group of mixed males, females and babies. There is no accurate population census for the walrus but it is believed there are over 200,000 Pacific walrus and only a few thousand Atlantic walrus individuals. They have been heavily exploited by man for food, hides, and their ivory tusks.

Walruses can be found in most areas of the Arctic Ocean feeding on benthic shellfish. Resting walrus group with the author and her husband, Svalbard, August 2003. Walruses spend one third of their time on land or pack ice and the other two thirds in the ocean. They appear awkward on land but graceful in the water where they feel most comfortable. A walrus can live for forty years or more and is, indeed, a unique and marvelous creature of this earth. Resting walrus group with one member awake. Notice the walrus with its tusks raised as it squints to see who is nearby. Walruses have poor eyesight but are very curious. When groups are asleep and people come near them you must move slowly and quietly so as not to disturb the entire group. One by one they wake up and look around to see what is happening, then go back to sleep. If they are startled they may all rise and stampede to the water ... trampling the babies or young ones. Walrus tusks are found on both the male and the female where they grow continually throughout their life. The tusks are used as a symbol of age, sex, and social status.

The babies have no tusks when they are born. The tusks of the males are much longer and wider in proportion to their body than those of the female. The males use their tusks as a symbol of their masculinity � turning their heads and thrusting their tusks up in a show to prove their dominance. Tusks are also used as weapons in fighting, to help in walking on land (the toothwalkers) and they have a minor role in feeding. Walrus head showing red eye and no external ear (left). Walrus showing typical rumpled brown body (right). Walruses have no external ear, an adaptation to the cold (reducing any external appendages). It is just a small hole which is hard to see with all of their wrinkles. The fat body with rumpled brown skin is characteristic of adult walruses. Rosy skin showing through their rumpled brown flesh is common on walruses who have been in the sun for some time. Rosy skin of sunning adult walruses is typical after several hours in the sun. As walruses age they tend to loose their brown hair so the older adults may appear almost hairless.

The color of their skin can change from being very pale to rosy pink. This color change is because of their circulation that is restricted to the outside when they are in cold water (to conserve heat). When they are on land the circulation is restored and they often have a rosy hue. Small head, large tusks, and red eyes of the walrus. Their rounded, streamlined body makes them well adapted for swimming and to conserve heat. By having a small surface to volume ratio with few external appendages there is a decreased surface area in which to loose heat. Thus the bulbous body of the walrus, small head without any external ear flaps (pinna) gives them a hydrodynamic shape. It is also insulated from the cold by a thick layer of blubber under the skin (up to 6 inches thick). The male walrus lacks any externally visible penis � the walrus penis is internal and supported by a bone called a baculum. Walrus baculum (penis bone). Walrus hind limbs can bend under their massive bodies (left). Close up view of hind limbs under body (right). Their forelimbs and hindlimbs are sleek and webbed, like oars.

The walrus swims mostly with its hind limbs, using the front limbs as rudders. They are rather slow swimmers averaging only about four and a third miles per hour. But, if they are startled they can swim up to 22 miles per hour. On land, the hind limbs are brought around and under the body (similar to sea lions and fur seals) but the walrus cannot hold up its own weight so it moves on land (or on the pack ice) like an inchworm, thrusting its body forward in small lunges using its limbs but never really getting off the ground. Its thick layer of blubber acts as a cushion on its chest and tummy area. A typical male walrus (left). Male walrus tusks in a museum in Norway with the author and her husband for scale (right). The male walrus is usually called a �bull� and gets to be over ten feet long and weighs over 2,650 pounds. The full sized adult males may have tusks over three feet long. These older adult males usually develop a cornified chest and shoulder area which aids them in any battles they may have as they lung against their opponent. A typical female walrus.

The female walrus is usually called a �cow� and is smaller than the male with tusks that are smaller � generally not over two feet long. Females only get to eight and a half feet in length and weigh up to 1,800 pounds. Walrus resting in shallow water on its tusks with its nose open. Walrus with nose closed. Walruses feed on benthic shellfish like clams, whelks, cockles, and mussels. They dive to depths of 300 feet and can stay down for over ten minutes on the average feeding dive. One dive was clocked at 27 minutes. When they dive to feed their ears close and their nostrils close tightly. Special tissue in their ears allows them to equalize the pressure easily. An adult walrus might feed on 4,000 clams in one day but then rest for up to four days before feeding again. Walruses swimming out to greet our boat - one diving behind the greeting party. Walruses have special adaptations for diving. They have a larger percentage of blood in their bodies to carry oxygen � about 12 percent of their weight as compared to only 7 percent for humans.

Also, their red blood cells (that carry the oxygen) are exceptionally large. In addition, they have lots of myoglobin in their muscles that can store oxygen. When they dive the blood flow is cut off from their skin, extremities and stomach. All of these adaptations allow for an efficient and lengthy use of oxygen stores. After diving walruses can inflate throat pouches with air so that they can rest at the surface. These unique throat pouches are actually called �pharyngeal pouches� and act like a life preserver. The males use them to make a loud bell-like sound during breeding season. Walrus whiskers close up. While diving for shellfish walruses use their tusks as sleds and their whiskers (vibrissae) as feelers. They will sled along the bottom of the ocean looking or feeling for their prey. When prey is detected the walrus will stop, swish its head back and forth to dig it out. It uses its vibrissae like �chop sticks� to manipulate it. If the shellfish is too far below the surface the walrus will squirt water forcefully through its tongue and hydraulically drill out the shellfish.

Then the walrus will suck out the soft insides of the shellfish. The ability of the walrus to suck out the insides of the shellfish is remarkable as they can do this in a matter of seconds � leaving the empty shell beside the depression it made to dig out the shellfish. Sometimes there is a tough skin on the siphons of the shellfish that remains attached to the empty shells but has been pulled �inside out� by the strong suction power of the walrus. Some calculations show that a walrus can find and eat a shellfish in about six seconds. This speed allows the walrus to consume plenty of food on a dive. Mother and baby walrus - notice the short tusks on the baby. The walrus has the lowest reproductive rate of all the pinnipeds. The females only have a calf every two to three years. The babies stay with their mother for over two years. Although the males mature at about 10 years of age and the females at about 8, most males do not mate until they are at least 15 and females usually do not give birth until they are around 10 years old.

Tusk display by a walrus in the water - by throwing their head back and showing their tusks the walrus is announcing its presence and warning others to leave it alone. Angry tusk display. Mature male walruses claim an aquatic territory near a group of resting female walruses. The strongest males get the best territories and keep them by displaying their tusks, growling and lunging at nearby males. These territories are constantly shifting as the ice moves. The males submerge under the water and make calls for a few minutes at a time. At the surface they make clacking sounds with their jaws. It is quite a scene with the males spaced some thirty feet apart � all doing the same thing. Although they make threat displays toward each other there is rarely an injury. The females come to the males, one by one, and join him in the water. The pair will nuzzle each other, dive together and mate in the water. Occasionally they will leave the water to mate on land but the courting occurs in the water. Each male may mate with several females each season but the females only choose one male.

Mating is helped in these bulky creatures by the fact that the males have a bone in their penis to aid in mating. Their penis is held internally until reproduction when it is extended by the use of this penis bone (called a baculum). Walruses have the longest baculum of any living mammal. (Baculums are also found in foxes, seals and polar bears). Walrus baby. Walrus babies are born in May or June. The walrus has �delayed implantation,� like many other pinnipeds which allows a variety of mating times but the fertilized egg (zygote) waits and implants at the exact time within each female so that the babies are born within a month or so each year. This produces a yearly cycle even though the gestation period is different than a year. Most babies are born as the females are moving north (following the pack ice) to feed. The babies are born with their moustache but not their tusks and are usually about 100 pounds. The babies can swim within minutesof their birth. The females produce very rich milk (30 percent fat) and nurse their babies at sea.

They are also known to take excellent care of their babies, protecting them from harm and even carrying them on their back or clutching them to their chest. Walruses from afar on a cloudy day. The walruses follow the edge of the pack ice each year. They huddle in herds during the winter resting on the ice. If it gets too cold they enter the water (which is often warmer than the air in winter). They must be careful if they are hauled out near a lead (channel of water) that the lead does not freeze over and prevent them from entering the water. The walrus can use is tusks to chip the edges of a breathing hole in the ice to keep it clear and give them access to the water. They also use their tusks to help haul themselves out of the water. If they are caught in the water with ice above them they can break up to eight inches of ice with their head from underneath the ice to create a breathing hole. Walrus. Every spring the walruses go north to feed, with the melting edge of the pack ice. They feed all summer long.

During this time the sexes may separate � groupings of all males may be found on the more southerly land areas hauled out together to shed their hair and skin and sleep. The females make the journey north � giving birth along the way. Curious walruses. During fall the walruses stay along the edge of the ice as it extends to the south. The walruses who have traveled north (mostly the females and babies) return to the south and the herds are reunited. During the dark, and icy winter the herds huddle together and mating occurs. All the Pacific walruses funnel through the Bering Strait during this yearly migration north and south (up to 2,000 miles). The Atlantic walruses have a certain number of females that do not migrate north each year but stay with a mixed herd. Other Atlantic walruses sexually segregate (like the Pacific walrus) during the summer. Walrus group. The main predators of the walrus are polar bears, killer whales, and humans. Humans have hunted the walrus since the days of the Vikings and early Native Americans.

It is the Atlantic walrus that was the hardest hit by humans because the population centers of the world were in their area (northern Europe) for the longest time. By the mid 1800s there were virtually no walruses in Svalbard. Now the walrus has circumpolar protection and is generally hunted only by native populations for dietary, craft or art. The walrus used to be used as a source for meat for the sled dogs of the north � these sled dogs have been replaced by skidoos (snow mobiles) now. The only main problems today are with poachers or native populations who may choose to kill the walrus for its tusks and sell them on the black market. Walrus tusk. Pollution may be a problem for the walrus. The fatty tissues of the walrus show high levels of some heavy metals and PCBs (polychlorinated biphenyls). In Alaska there are high levels of both cadmium and mercury found in walrus livers. These chemicals may cause developmental problems, cancer, damage to the nervous system and/or reproductive decline. Populations of the Pacific walrus are rebounding nicely.

Some 80 to 90 percent of the world�s walruses are Pacific walruses found in the Bering Sea area and the Chuckchi Sea as well as a separate group in the Laptev Sea. Walrus range map. Pacific walrus is in lavender, Atlantic walrus is in rose. (NOAA edited image) Populations of the Atlantic walrus are still very low. These animals are found in three separate groups - in the area above Scandinavia (including where they have repopulated Svalbard waters now), on the eastern side of Greenland, and above Canada stretching to western Greenland. For further information I recommend an excellent book by Peter Knudsen entitled The World of the Walrus, published by Sierra Club Books, San Francisco. It has interesting pictures as well as outstanding text. (Revised 6 August 2007) Physical Characteristics Size Male Pacific walruses weigh about 800 to 1,700 kg (1,764-3,748 lb.) and are about 2.7 to 3.6 m (9-12 ft.) long.

Female Pacific walruses weigh about 400 to 1,250 kg (882-2,756 lb.) and are about 2.3 to 3.1 m (7.5-10 ft.) long. Atlantic walruses are slightly smaller: males weigh about 908 kg (2,000 lb.) and reach lengths of 2.4 m (8 ft.). The northern and southern elephant seals are the only pinnipeds that, when full-grown, can be larger than the walrus. Body Shape A walrus has a rounded, fusiform body. Coloration Generally, walruses are cinnamon-brown overall. Walruses appear quite pale in the water; after a sustained period in very cold water, they may appear almost white. They are pink in warm weather when tiny blood vessels in the skin dilate and circulation increases. This increased skin circulation sheds excess body heat. Calves at birth are ash gray to brown. Within a week or two, calves become tawny-brown. The coloration pales with age. In general, younger individuals are darkest. Flippers Limbs are adapted as flippers. Flippers are hairless.

The skin on the soles of a walrus's flippers is thick and rough, providing traction on land and ice. The foreflippers, or pectoral flippers, have all the major skeletal elements of the forelimbs of land mammals, but are shortened and modified. A walrus's foreflippers are short and square. Each foreflipper has five digits of about equal length. Each digit has a small and inconspicuous claw. Walruses have short, square fore-flippers with five digits of about equal length. Each digit has a small, inconspicuous claw. While swimming, a walrus holds its foreflippers against its body or uses them for steering. On land, a walrus positions its foreflippers at right angles to the body for walking. Walruses have triangular-shaped hind flippers. Hind flippers have five bony digits. Claws on the three middle digits are larger than those on the outer two digits. Walruses use alternating strokes of the hind flippers to propel themselves in water. Like sea lions, walruses can rotate their hind flippers under their pelvic girdle, enabling them to walk on all fours.

Head A walrus's head is square and broad with conspicuous tusks and whiskers. A walrus's head is square and broad with large tusks and whiskers. A walrus has about 400 to 700 vibrissae (whiskers) in 13 to 15 rows on its snout. Vibrissae are attached to muscles and are supplied with blood and nerves. Most walruses have 18 teeth. The two canine teeth in the upper jaw are modified into long ivory tusks. Both males and females have tusks. The tusks of males tend to be longer, straighter, and stouter than those of females. Tusks erupt during a calf’s first summer or fall. Tusks can grow to a length of 100 cm (39 in.) in males and 80 cm (31.5 in.) in females. Tusks grow for about 15 years, although they may continue to grow in males. The primary functions of the tusks are establishing social dominance and hauling out onto ice or rocky shores. Eyes are small and located high and toward the sides of the head.

Ears, located just behind the eyes, are small inconspicuous openings with no external ear flaps. Paired nostrils are located on the snout above the vibrissae. Nostrils are closed in the resting state. Walruses have paired nostrils that are closed in the resting state. Tail Walruses have a tail, but it is usually hidden by a sheath of skin. Skin and Hair A walrus's skin is thick and tough. It may reach a thickness of 2 to 4 cm (0.79-1.6 in). It is thickest on the neck and shoulders of adult males, where it protects the animal against jabs by the tusks of other walruses. The skin of males often has large nodules; these are absent in females. Because the nodules appear at the time of puberty, they are presumed by some researchers to be a secondary sex characteristic. Male walruses have large nodules on their skin that appear during puberty Hair is about 7 to 12 mm (0.3-0.5 in.) long over most of the body. It is shortest on the face and absent on the flippers.

Hair is densest on juveniles and becomes less dense with age. Molting. An annual molt (hair-shedding) for most males takes place from June to August. Females molt over a more prolonged period. Molting in walruses is gradual - individual hairs fall out and are replaced. Calves shed a fine prenatal coat, called lanugo, about two to three months before they are born. They molt again at about one to two months. Walrus Walrus IUCN STATUS (2010) - DATA DEFICIENT Distribution and Numbers Easily recognised by its long tusks, the walrus is the only living member of the Odobenidae family of pinnipeds and has two generally recognised subspecies. The Atlantic walrus (O.r. rosmarus) is found from the east Canadian Arctic eastwards to the Kara Sea. The Pacific walrus (O.r. divergens) is found in the north Pacific Ocean and in Arctic waters from the East Siberian Sea to the western Beaufort Sea, as well as in the Laptev Sea.

It has been proposed by some scientists that the Laptev Sea population be given subspecific status as the Laptev walrus (O.r. laptevi) but this is not widely accepted. Accurate data on walrus abundance is not available but the most recent rough population estimates have been 22,500 Atlantic walruses (6,000 in Norway and Russia, 12,000 in Canada and 4,500 in Greenland), and a minimum of 200,000 Pacific walruses in eastern Russia and the United States. Status Walruses are long-lived and have a relatively low reproductive rate, so their numbers are easily influenced by hunting and other mortality. Both subspecies of walrus have been subjected to intensive commercial hunting in the past for their blubber oil, tusk ivory and skins, leading to the extermination of local populations in some areas and severe depletion of others. Although commercial hunting has now ceased, other forms of hunting currently have the most direct and quantifiable impact on walrus populations. Native subsistence hunting of the walrus for its meat, skin, ivory, oil and other products has taken place for thousands of years and continues today.

Lack of accurate information on walrus population numbers means that hunting quota levels may be having a detrimental effect on the species, particularly for the Atlantic walrus. Certainly the problem of walruses being "struck and lost" results in kill statistics that are very probably underestimated, figures of 30-42% having been quoted for the percentage of walruses killed in this way. Walruses are also conservative in their choice of habitat and food, so any reduction in these may have detrimental effects on their numbers. There are serious concerns that walrus numbers may be threatened by a loss of sea ice caused by global warming and environmental changes, the retreating sea ice reducing the availability of suitable habitat and food supply. Some concern has also been expressed at the effects of bottom trawling for flatfishes on walrus habitat near haulouts in Bristol Bay, dragging of the sea bed by fishermen having been known to disturb and destroy walrus feeding habitat. Other potential threats to walrus populations include pollution and disturbance from oil and gas exploration and extraction, especially in the Bering and Chukchi Seas, around Svalbard and in the western Russian Arctic.

Walruses are particularly at risk from oil spills as their staple diet of benthic invertebrates are known to accumulate hydrocarbons. High concentrations of metals, notably cadmium, lead and mercury, have been found in Atlantic and Pacific walruses, while high levels of organochlorines such as DDT and PCB have also been found in those walruses that eat seals. Disturbance from sources such as tourism and fisheries is also a concern, particularly as walrus calves may be trampled underfoot during disturbance-caused stampedes of hauled out walruses. Calves separated from their mothers in the first year of nursing are thought to have little chance of survival, and several haulouts have been completely abandoned by walruses due to disturbance. The walrus is listed as an Appendix III species by Canada under CITES and as an Appendix II species under the Bern Convention. The Laptev walrus is listed as Data Deficient on the IUCN Red List. Atlantic Walrus: Its numbers having been decimated in the past, mainly by European sealers and whalers, the Atlantic walrus has not been able to recover and is still well below its pre-exploitation level of several hundred thousand.

It is currently believed that there are eight subpopulations of Atlantic walrus, scientists concluding in 1995 that four of these were thought to be stable or increasing, two to be declining and two to have unknown status. In 1995 it was calculated that the native kill of Atlantic walrus, including those struck and lost, totalled about 1,150 per year. The native kill of Atlantic walrus takes place mostly in Canada and Western Greenland. Hunting of walrus in Norwegian waters (including the Norwegian Arctic) and the Russian western Arctic has been banned since 1952 and 1956 respectively, although there is some poaching in Russia, especially since the collapse of the Soviet Union. There are also reports of a trade in walrus calves as part of the Russian exotic animal market. A survey of hunters and elders from Nunavut in the Canadian Arctic, released in September 2000, revealed that hunters had observed walruses and other wildlife with a large number of deformities, including swollen internal organs and missing patches of skin.

A strange occurrence of "round wounds" was observed in the skin of some walruses, and the analysis of a similar abnormality found in a walrus in March 2000 had pinpointed a strain of bacteria as the cause. Hunters also reported finding walruses with fluid or pus between their meat and fat or with unusual stomach contents, and even one walrus which had its gall bladder reversed and draining into its stomach. Changes in the colour of walrus meat and fat were also reported. The survey report recommended a specific system of monitoring for such abnormalities in the future, as well as further studies on affected animals. One possible reason suggested for these abnormalities is the high level of persistent organic pollutants (POPs) in the Canadian Arctic. Pacific Walrus: Commercially exploited since the 18th century, the Pacific walrus has been substantially reduced in numbers and allowed to recover three times in the past 150 years. The population was most recently reduced to 50,000 - 100,000 in the mid-1950s.

Conservation measures were initiated in both Russia and the United States in the 1960s and these have allowed the subspecies to attain levels close to those it had before exploitation. Trends in life history parameters indicate however that the population may now be declining. The lack of a proper range-wide survey since 1990 along with reports by scientists and native hunters of lower calf production and survival has led to increased concern for the population's status. Photo: Kathy Frost, Alaska Department of Fish and Game When threatened, walruses vigorously defend themselves, their calves and often their colleagues. Walruses feed mostly on invertebrates that live in or on the bottom sediments, almost exclusively on bivalve molluscs, such as clams, when these are available. The species' diet also includes worms, sea cucumbers, snails, crustaceans, and occasionally seals. Fish are eaten only rarely and the taking of the occasional bird has also been observed. The walrus uses its stiff whiskers to locate its food, often feeding in total darkness in the winter.

Any food requiring to be dug out from the sediment is either rooted out by the walrus by using its snout, by jetting water at it with its mouth, or by waving its front flippers. The maximum recorded dive for a walrus is a depth of 113m for almost 25 minutes, but individuals are thought to be able to dive deeper than this. Walruses, particularly calves, are preyed upon by polar bears and killer whales. Statistics Walrus measurements vary between populations but in general there is no significant difference in the body size of male Atlantic and Pacific walruses, whereas female Atlantic walruses have been found to be significantly longer than their Pacific counterparts. Adult male Atlantic walruses measure 3m in length and 1,200-1,500kg on average (maximum 2,000kg), while adult female Atlantic walruses measure 2.7m in length and 600-700kg on average (maximum over 1,000kg). Calves of both subspecies are born measuring 1.2m in length and weighing 60kg on average.

Females reach sexual maturity at 4-10 years, males at 6-10 years, although males cannot compete successfully for females until they are about 15 years of age. Walruses can live to be at least 40 years of age. Please Donate! Facts about Walruses - Walrus Facts and Information Facts about Walruses by Walrus-World | Nov 22, 2013 | Facts | Facts about Walruses How much do you really know about the walrus? Chances are there is plenty about them that you haven’t heard about before. As you read these walrus facts you can be confident that your knowledge about them is going to continue to expand. The name of the walrus means “tooth walker”. The tusks of a full grown walrus can weigh 12 pounds. Each one features from 400 to 700 whiskers. From adistance the walrus appears to be without fur. However, the entire body is covered with a very thin layer of it. The blubber, which is the layers of fat, on a walrus can be more than 4 inches thick.

A walrus can remain under water for up to 30 minutes before coming up for air. During migration they can travel up to 1,800 miles. The females tend to migrate further than the males. They can stand very cold water that is as low as -31 degrees Fahrenheit. When a calf is very young it will ride on the back of its mother in the water. However, it does know how to swim on its own. This method of movement is for protection and for bonding. One of the leading causes of death for the walrus is due to various types of parasites in the water. They are able to cause problems for the skin as well as internal infections that shut down the normal functions of these animals. Males often kill each other during their fight for the right to mate or in an effort to move up the social status ladder. Females often keep their young underneath them to prevent them from being crushed by other adults in the area. The skin of a walrus is very thick. This offers it protection from the extremely cold water as well as from many of the different predators out there. The walrus can change colors and it has to do with their skin and their body temperatures.

This is all due to the fact that their blood vessels change in size when it is cold versus when it is warmer. For example when it basks in the sun the skin turns red due to the amount of blood that rushes to the skin. The walrus spends the cold winter months over the Bering Sea. It is common for them to pass through the Bering Strait during their migration patterns. One of the most amazing things about the walrus is that they are able to sleep while they are swimming! This is possible due to the air sacs that are located in the throat region. There is only one species of walrus which is quite interesting. Most animals out there have many species so this is a fact that helps to identify them as unique in the eyes of researchers as well. Many people don’t realize that the walrus molts. This occurs in June or August as they no longer need their heavy winter coat. When a walrus needs to break ice, it will do so by slamming its head against it. Then it will use the tusks to make the hole in the ice as large as it needs to. This process allows them to have breathing holes so they can stay under water for longer periods of time.

They have to come up for air, but not all the way to the surface. For a very long time it was unknown how they were able to stay under water for so long. Now it is known that they are getting air but just from another source. Categories Biogeography of Army Ants The Biogeography of the Pacific Walrus (Odobenus rosmarus divergens) by Garrett Dunwoody, student in Geography 316, fall 1999 General Information The Walrus species (Odobenus rosmarus) is part of a group of mammals known as pinnipeds. The walrus is the largest of the pinnipeds within the Arctic and subarctic seas. In general, the walrus tends to be found in shallower waters, close to ice or land (Alaska Department of Fish and Game 1999). Two sub-species of walrus are recognized: the Atlantic Walrus (Odobenus rosmarus rosmarus) which tends to be smaller than its counterpart the Pacific Walrus (Odobenus rosmarus divergens) (Wilson and Reeder 1993).

Total Taxonomic Classification of Odobenus rosmarus divergens The following information was gathered at the web site (Smithsonian Natural History Home page 1999) Kingdom-Animalia Evolution It is believed that walrus evolved during the Oligocene Era from bear or dog like ancestors of the North Pacific (Riedman 1990). In relative terms the walrus is new to the North Pacific region. The presence of these animals, in accordance with fossil record, date back to one hundred thousand years ago. It is believed that walrus first entered this region from the northwest via the northern coast of Eurasia (USDI 1982). The genus Odobenus constitutes a separate order Pinnipedia. However, it is customary to consider them as a suborder within the family Carnivora (Gittleman 1989). The origin of pinnipeds is not clear especially when referring to the walrus. The modern view, however, is that they are monophyletic. Biologists have been arguing over pinniped evolution for years.

If it is true that pinnipeds are monophyletic it would mean that walrus would be more closely related to other pinnipeds than to its relative the otter. Studies do show that walrus are in fact monophyletic and that they are more closely related to other pinnipeds than to mammals (Riedman 1990). Perhaps this controversy about the origin and evolution of the walrus is largely due to the aggressive behavior of the walrus and that its instincts more closely resemble that of the family carnivora. Physical Appearance The male walrus tends to average a larger body and tusks than the female walrus (Renouf 1991). The most distinguishing feature of all walrus are its tusks, which are carried by male and female. These canines have been measured at lengths of one meter (Carling 1999). Overall, walrus are considered to be cinnamon brown in color. However, this will vary with sex and age. In general younger walrus will be the darkest where their skin is highly pigmented and their hair will be almost black (Ridgeway et al. 1981).

In a comparison of standard lengths of males and females males are on the average of 50 cm longer than the average female. However, there is a overlap in size. Out of the specimens sampled the males range in size from 279-356 cm and females range from 230-312 cm. Not only do males tend to be longer, on average they weigh 400 kg more than female walrus. Where males weigh 1,210 kg (2667 lbs.) females will only weigh 832 kg (1834 lbs.) (USDI 1982). Habitat Walrus are considered pagophilic pinnipeds, which means, ice loving. Pagophillic pinnipeds prefer to haul out on ice, however, they will also come ashore on rocky islands when ice is not available (Reidman 1990). It is observed that walrus will not stray far from the ice edge. The highest density of walrus lie within the nearest 37 km of the ice edge (Gilbert 1989).

The Pacific walrus fulfills a particular niche within the ecology of the Bering and Chukchi Seas. Walrus are bottom or benthic feeders that disturb and physically alter the sea floor (Fay et al. 1997). Walrus need to inhabit seas and oceans in which the bottoms and banks are covered with an extensive variety of shellfish. Due to seasonality and ice coverage the walrus is forced to follow food sources. The walrus ability to locate food is largely dependent on the amount and type of ice present; this results in elaborate migratory patterns (Perry 1967). Population Walrus populations are circumpolar, however, they are not uniformly distributed (Carling 1999). There are many areas in the Arctic where there is low or no population of walrus. The discontinuity of this species suggests that there are isolated populations with little or no chance to interbreed. In many cases the populations of particular walrus species are separated by twelve hundred kilometers of unpopulated seas and oceans (USDI 1982). Over the last one hundred and fifty years the population of walrus has fluctuated .

The original population of walrus is unknown; however, estimates point in the direction of two hundred to two hundred and fifty thousand animals. The walrus population was believed to reach its lowest in the mid 1950s where population was estimated to be between fifty and one hundred thousand. In the latest estimations walrus population is seeing a recovery with a recorded population of roughly two hundred to two hundred and thirty thousand (Fish and Wildlife Service 1998). The Pacific Walrus (Odobenus rosmarus divergens) The Pacific Walrus is given its name due to the fact that they are found in the North Pacific Region of the Arctic, the Bering, and the Chukchi Seas (Fay 1981). The Pacific Walrus inhabits the area from the eastern East Siberian Sea through the Chukchi Sea all the way to the western Beaufort Sea and southward to the waters of the Bering Sea. The majority of the population of the Pacific Walrus will congregate in the summer months in the southern regions of the Chukchi Sea. The remaining population, which consists of mostly adult males, tends to remain further north in the Bering Sea and Bristol Bay.

In winter months these species will tend to follow areas that produce a thinner layer of pack ice, however, the exact migration and location will vary due to the magnitude of seasonality (Fish and Wildlife Services 1998). Migration The following explanations are monthly records of The United States Department of the Interior (1982). January In the month of January more than 90% of the northern seas are covered by heavy ice. Due to this phenomenon very few walrus sightings occur in January. This is mostly due to the fact that most have traveled southward prior to the development of the heavier ice. February February is the coldest month where pack ice extends south to the edge of the continental shelf. Walrus sightings are increased when compared to January. March The number of walrus sightings is increased in March. This is partly due to a fall in wind and a moderation in temperature. March provides a very good model for the winter distribution of the walrus. April During this month the water of the Bering Sea is much warmer largely due to the duration and angle of solar radiation. The ice pack is diminishing. This is evident with a larger percentage of the population present, along with a migration northward to cooler waters.

May By this time of year new ice formation has ceased. Surface winds are warmer and weaker. A large walrus population passes through the Bering Strait and northward. June The ice pack of the Bering Sea continues to diminish. By June what remains of the population will move northward through the Bering Strait. July With the warmer months the walrus moves northward to roughly 70 degrees N Latitude. The walrus remaining south of the Bering Strait will remain there for the summer months. August August usually begins with a slight recession of the ice pack. At this time the walrus move north westwards towards Wrangell Island. The geographic range of walrus at this time is from the Bear Islands east of Siberia to roughly 74 degrees N Latitude. September At this time the majority of walrus population is above 70 degrees N Latitude. October Due to the formation of new ice the walrus travels southward. Much of the walrus population congregates at the Bering Strait. November The ice pack moves south to the Bering Strait where the majority of the population of walrus is at rest between St. Lawrence Island and the ice pack of the North. December The ice sheet has moved south past St.

Lawrence Island where part of the population of walrus remains. However, much like January very few sightings occur. References Cited Alaska Department of Fish and Game, 1999. Notebook Series. Carling, M. 1999. University of Michigan. Museum of Zoology Animal Diversity Web. Fay, F.H. 1981. Walrus Odobenus rosmarus. pp.1-24. In Ridgway, S.H. and R.J. Harrison,eds. Handbook of Marine Mammals. London: Academic Press Inc. Fay, F.H., L.L. Eberhardt, B.P. Kelly, J.J. Burns, and L.T. Quakenbush. 1997.  Status of the Pacific Walrus Population, 1950-1989. Marine Mammal Science13(4):537-565. Fish and Wildlife Service,1998. Marine Mammals Management-Walrus Program. Gilbert,J.R.1989.

Aerial Census of Pacific Walruses in the Chukchi Sea. Marine Mammal Science5(1):17-28. Gittleman, J.L. 1989. Carnivore Behavior, Ecology, and Evolution. United States. Cornell University Press. Perry, R. 1967. The World Of The Walrus. New York. Taplinger Publishing Company. Renouf, D. 1991. Behaviour of Pinnipeds. Great Britain. Chapman and Hall. Ridgway, S.H. Harrison, R.J. 1981. Handbook of Marine Mammals. London. Academic Press. Riedman, M.1990. The Pinnipeds Seal, Sea Lions, and Walrus. Berkeley, Ca. University of California Press. (USDI) United States Department of the Interior. 1982. Ecology and Biology of the Pacific Walrus, Odobenus Rosmarus Divergens Illiger. Washington D.C. Wilson D.E. and D.M. Reeder.1993.

Mammal Species of the World A Taxonomic and Geographic Reference. Washington. Smithsonian Institution Press. Walrus Facts Walrus Facts By Alina Bradford, Live Science Contributor | November 21, 2014 09:22pm ET MORE Walruses on ice afloat in the Bering Sea. Millions of years ago, there was no ice to be found in the region. Credit: Liz Labunski/USFWS. Walruses are the gentle giants of the Arctic. They are among the largest pinnipeds — fin-footed, semiaquatic marine mammals. However, while they have an intimidating size, and are carnivores, these animals are not aggressive. Size Walruses have large, flabby bodies covered in brown or pink skin. Short fur covers most of their bodies except for their fins. Their faces feature two small eyes, a mustache and two long tusks.

Walruses weigh from 600 to 1,500 kilograms (1,320 to 3,300 lbs.) and can be as long as 3.2 meters (10.5 feet), according to the Animal Diversity Web (ADW), a database maintained by the Museum of Zoology at the University of Michigan. Males are about twice as big as females, have longer and thicker tusks, and usually have thicker skin. Walrus tusks can grow up to 3 feet (1 m). The tusks are canine teeth and stick out from either side of the animal's mouth. Walruses use their tusks to break through ice, and to assist in climbing out of the water and onto the ice. The animals also use their tusks to defend themselves from larger predators and to establish dominance and a hierarchy among walruses, according to the ADW.[ Giants on Ice: Gallery of Walruses ] Habitat Most walruses live in frigid waters near the Arctic Circle. They prefer areas with shallow water so they can easily access food, according to the ADW. Want to see where these big walruses hang out, besides the beach?

Slap a tag on one and see. Credit: USGS. Walruses climb up on ice or beaches to sleep or to rest. They don't move quickly on land but are swift in the water. Walruses can swim on average around 4.35 mph (7 km/h) and as fast as 21.74 mph (35 km/h), according to the MarineBio Conservation Society . A group of walruses is called a herd. They gather by the hundreds to sunbathe on the ice. During mating season, walruses amass by the thousands. A herd is usually segregated by gender; females have their own herds, and males have their own herds. The dominant males are chosen by age, body size and tusk length. Walruses are very fat, but for good reason. Their blubber keeps them warm in frigid waters. These animals can also slow their heart rates, which allows them to live in freezing temperatures, according to National Geographic . Diet Walruses are carnivores, but they aren't ferocious hunters. The walrus' favorite food is shellfish. They dive underwater and use their whiskers to detect the shellfish in the dark waters of the ocean.

According to the Smithsonian Institution's Arctic Study Center , a walrus can eat up to 4,000 clams in one feeding. When food is hard to come by, walruses will also eat the carcasses of dead seals. Offspring Female walruses give birth to their young, called calves, during their migration in the springtime. After a gestation of 15 to 16 months, the female will give birth to one calf. Very rarely, walruses will give birth to twins. Calves weigh around 100 to 165 lbs. (45 to 75 kg) at birth, according to Defenders of Wildlife . A walrus pup separated from its mother in the Arctic Ocean. Credit: Phil Alatalo, Woods Hole Oceanographic Institution As soon as the calf is born, it can swim. It will swim along with its mother for the first three years of its life. Then, at 3 years old, the male calves will go off to live with the male herd. At 15, the male will start to mate. Females will mate as soon they reach 5 years old. Walruses can live up to 40 years.

Classification/taxonomy There are three subspecies of walrus. Atlantic walruses live in the coastal areas along northeastern Canada to Greenland. Pacific walruses live in the northern seas near Russia and Alaska. Laptev walruses live in the Laptev Sea of Russia. Some scientists contest that the Laptev walrus is not a third subspecies, and say that it should be lumped together with the Pacific walrus, according to the International Union for Conservation of Nature's (IUCN) Red List . The Integrated Taxonomic Information System (ITIS) places the walrus in a suborder that is made up of doglike carnivores, which includes seals, coyotes, foxes, jackals, wolves, skunks and bears. The taxonomy of walruses is: Kingdom: Animalia Family: Odobenidae Genus & species: Odobenus rosmarus Pacific Walrus Species Profile, Alaska Department of Fish and Game Alaska Department of Fish and Game Pacific Walrus (Odobenus rosmarus divergens) Species Profile Some walruses kill and eat seals and seabirds. Special Status Listing: Yes, see Status, Trends and Threats.

Fast Facts General Description The Pacific walrus is a large pinniped (i.e., the group that includes seals, sea lions and fur seals) that lives in the Bering and Chukchi seas where they haul out on sea ice and along the mainland coast and islands of Russia and Alaska. Walruses are strong bodied and have a very thick, tough hide that can be an inch thick. The most distinctive feature of walruses, both male and female, is their two ivory tusks, which are long upper canine teeth that grow throughout their life. Walruses also have hundreds of short, strong, highly sensitive whiskers that they use to search the seafloor for their food. Adult males, or bulls, are up 12 feet long and may weigh up to 2 tons; although females are smaller they can weigh more than 1 ton. Bulls are identified by their larger size, broad muzzle, heavier tusks, and many large bumps on their neck and shoulders called “bosses”. Life History Reproduction and Growth Females begin breeding at 6-7 years of age and generally give birth every 2 years.

Males are mature at 8-10 years of age, but generally cannot successfully compete against older, larger males for females until they are 15 years old. Walruses may live up to 40 years. Unlike the other Alaskan pinnipeds, walruses mate in the water during the winter months (January-March). However, delayed implantation of the fertilized egg is suspended from further development for several months, resulting in a total gestation period of 15 months, the longest of all the pinnipeds. Walrus calves are born on ice floes in late spring and weigh approximately 140 pounds. Calves typically stay with their mothers for two years and weigh approximately 750 pounds when they become independent. Feeding Ecology Walruses eat a wide variety of soft invertebrates found on or below the seafloor by using their sensitive whiskers to search for prey. Prey items include, clams, snails, worms, sea cucumbers, and tunicates. Except for their tusks, walrus teeth are flat; as a result, walruses eat by sucking food into their mouths using the powerful suction created by pulling their piston-like tongue back quickly.

Walruses suck out the soft parts of clams and snails leaving the shells to fall to the sea floor. Some walruses, mostly males, are known to occasionally prey on seals and seabirds. Behavior Walruses are highly social animals that travel and rest in large groups. The mother/calf bond, which lasts for approximately two years, is the longest and strongest among pinnipeds. Female walruses are known to become dangerously aggressive if their calf is threatened. When sea ice is not available, walruses will commonly rest on rocks, sandy beaches, and even grassy hills. Resting on land allows walruses the opportunity to form large social haulouts that can contain tens of thousands of individuals. Walruses use their tusks to help pull themselves onto rocks or ice, to move ice to create an opening to dive through, and to fight off predators. The most common use of tusks is social. Females will threaten and jab each other for better position on haulouts and during the breeding season, male walruses will threaten and fight with their tusks to compete for females.

When two males come together, they will raise and turn their heads sideways to display their tusks, and the walrus with smaller tusks will move away. If the two males have similar sized tusks, they will usually fight and may stab each other with their tusks, inflicting bruises and punctures. Walruses do not use their tusks for digging on the seafloor for food. Migration The Pacific walrus population spends the winter on the Bering Sea pack ice before separating in the spring. Beginning in the spring, females with young migrate northward from the Bering Sea to the Chukchi Sea, often passively moving with the receding sea ice. Most adult males migrate to Bristol Bay where they rest on land haulouts between foraging bouts. By late fall, walruses begin their return migration southward from the Chukchi Sea to the Bering Sea, ahead of the advancing sea ice. The males that remained in Bristol Bay head north to meet the returning population in the waters near St. Lawrence Island. Range and Habitat Pacific walruses range over the relatively shallow waters of the northern Bering and Chukchi seas, and are occasionally observed in the waters of the Eastern Siberian and Beaufort seas.

In the Bering Sea, walruses are distributed from the Bering Strait to Bristol Bay in the east, and in the west their range extends as far south as the Kamchatka Peninsula. They also use island haulouts near St. Lawrence Island and on the Pribilof Islands. Status, Trends, and Threats Status A 2006 aerial survey, conducted by the U.S. Fish and Wildlife Service (USFWS), estimated the population at 129,000, but due to the difficulties in counting walruses the confidence of that estimate is low and the possible range in population size is somewhere between 55,000 and 507,000. After reviewing available scientific and commercial information, the USFWS found that listing the Pacific walrus as threatened was warranted because of the decrease in sea ice caused by climate warming. Currently, however, the listing is precluded by higher priority actions to list other species. The USFWS will develop a proposed rule to list the Pacific Walrus as their priorities allow and will make any determination on critical habitat during development of the proposed listing rule. To learn more, visit the ADF&G Special Status page for Pacific walrus .

NatureServe: Global — G4 (Apparently secure), State — S3 (Vulnerable) ESA: Under consideration Trends Pacific walrus population size has varied substantially in the last 150 years, it increased between 1960 and 1980 and may have reached the carrying capacity of the marine environment. By the 1990s, the population was believed to be stable or in decline, and the current trend is unknown. Threats Potential threats to the Pacific walrus population include a reduction in sea ice, predation by killer whales and polar bears, and if traffic of large vessels increases there could be threats from pollution, ship strikes, and entanglement in trash. Specifically, recent changes in the thickness and duration of sea ice may affect walrus distribution and feeding opportunities as less ice is available. Walruses use sea ice as a stable, yet drifting, platform for resting between foraging trips, calving, and traveling. With less sea ice, walruses will likely spend more time on shore haulouts along the Russian and Alaskan coasts where foraging trips may be more limited to foraging grounds nearby.

Calves and yearlings suffer increased mortality on terrestrial haulouts when disturbances cause the herd to panic and rush to the water running over and crushing the smaller animals. Fast Facts Size Males average: 7–12 feet long, 2 tons; females average: 5–10 feet long, 1 ton Lifespan Up to 40 years old Distribution/Range Bering and Chukchi seas Diet Invertebrates that live on and below the seafloor – clams, snails, soft-shelled crabs, shrimp, worms, sea cucumbers; occasionally seals and seabirds. Predators Polar bears, killer whales, and Alaska Native hunters Reproduction Facts About Walruses 1. Walruses are related to seals and sea lions. Walruses are pinnipeds , which classifies them in the same group as seals and sea lions. The word pinniped comes from the Latin words for wing- or fin-footed, in reference to the fore- and hindlimbs of these animals, which are flippers.

There is disagreement over the classification of the taxonomic group Pinnipedia - it is considered by some as its own order, and by others as an infraorder under the Order Carnivora. These animals are well-adapted for swimming, but most (especially "true" seals and walruses) move awkwardly on land. Walruses are the only member of their taxonomic family, Odobenidae. More » continue reading below our video What are the Seven Wonders of the World Walrus. Courtesy Office of NOAA Corps Operations 7. Walruses insulate themselves with blubber. Walruses insulate themselves from cold water with their blubber . Their blubber layer fluctuates according to time of year, the animal's life stage and how much nutrition it has received, but may be as much as 6 inches thick. Blubber not only provides insulation, but can help make the walrus more streamlined in the water and also provides an energy source during times when food is scarce. Adult Female Walruses on Ice Floe with Young, in the US waters of the Eastern Chukchi Sea, AK, USA. U.S. Geological Survey/photo by S.A. Sonsthagen 8.

Walruses take care of their young. Walruses give birth after a gestation period of about 15 months. The gestation period is made longer by a period of delayed implantation, in which the fertilized egg takes 3-5 months to implant into the uterine wall. This makes sure that the mother has the calf at a time when she has the necessary nutrition and energy, and that the calf is born during favorable environmental conditions. Walruses usually have one calf, although twins have been reported. The calf weighs about 100 pounds at birth. Mothers are strongly protective of their young, who may stay with them for 2 years or even longer if the mother doesn't have another calf. Walruses resting on an ice floe in the Chukchi Sea. U.S. Geological Survey 9. As sea ice disappears, walruses face increased threats. Walruses need ice for hauling out, resting, giving birth, nursing, molting, and protecting themselves from predators. As the world climate warms, there is less availability of sea ice, especially in the summer.

During this time, sea ice may retreat so far offshore that walruses retreat to coastal areas, rather than floating ice. In these coastal areas, there is less food, conditions may become crowded, and the walruses are more susceptible to predation and human activities. While walruses are harvested by natives in Russia and Alaska, it appears from a 2012 study that an even greater threat than harvesting may be stampedes that kill young walruses. When fearing a predator or human activity (such as a low-flying aircraft), walruses may stampede and trample calves and yearlings. jeremkin / iStock Vectors / Getty Images 10. I Am the Walrus? Why did John Lennon declare "I Am the Walrus"? The answer is more related to author Lewis Carroll than the marine animal. To learn more, check out this article from the About.com Oldies Music Guide!

Question: How many tusks does a typical adult male walrus have?
Answer: 2