(Last Updated On: April 15, 2021)

Pacific walrus, the scientific name Odobenus roasmarus divergens dwells primarily in Arctic areas of the world, in the Bering Sea. In the heat summer months, it may travel so far as the Beaufort Sea and the East Siberian Sea. In this article, I am going to talk about Pacific Walrus vs Atlantic walrus, habitat, population, range, seal with big teeth, size, cute, etc.

Pacific Walrus profile

The Pacific walrus is a big pinniped (i.e., the group that features seals, sea lions, and fur seals) that lives within the Bering and Chukchi seas the place they haul out on sea ice and alongside the mainland coast and islands of Russia and Alaska.

Walruses are strong-bodied and have a really thick, robust disguise that may be an inch thick. The most distinctive function of walruses, each female, and male, is their two ivory tusks, which are long higher canine teeth that develop all through their life.

Walruses even have a whole bunch of quick, sturdy, extremely delicate whiskers that they use to look the seafloor for his or her meals.

Adult males, or bulls, are up 12 feet long and will weigh as much as 2 tons; though females are smaller they’ll weigh more than 1 ton. Bulls are recognized by their bigger size, broad muzzle, heavier tusks, and lots of giant bumps on their neck and shoulders known as “bosses”.

Two Pacific walrus populations are acknowledged, one in Russia’s Laptev Sea and the opposite, shared by Russia and Alaska, within the Bering and Chukchi seas.

The Laptev Sea inhabitants were as soon as thought of a separate subspecies however latest research help its recognition because of the westernmost inhabitants of Pacific walruses.

These populations could have shaped a continuum previous to business exploitation. Little information is on the market on the Laptev Sea inhabitants and its abundance and traits are unknown.

The Bering and Chukchi Seas inhabitants happens all through the continental shelf waters of each sea and ranged farther south previous to extreme looking. Population size has fluctuated markedly in response to various ranges of human exploitation.

Pacific Walrus Physical Description

Pacific Walruses are one of the many largest pinnipeds. The Pacific walruses are inclined to have a bigger body mass than the Atlantic walruses.

Pacific Walrus is thought for its large tusks, which are actually simply enlarged canine teeth. These tusks can break by 20 cm of ice. They additionally help walruses in climbing out of the water and onto the ice.

The tusks can be utilized for the walruses to defend themselves from bigger predators and are additionally an approach to set up dominance and a hierarchy amongst walruses. Tusks can develop to a size of 90 cm however the average size is roughly 50 cm.

Pacific Walrus has thick pores and skin that range from a light gray to yellowish-brown color. Walrus pup’s pores and skin color differs from the adult, as a result of they’re normally strong gray, whereas adults can range in colors.

The skin thickness varies throughout the body, however, is normally 2 to 4 cm thick. The layer of blubber beneath the pores and skin could be as thick as 25.4 cm.

Walruses have quick fur in most areas of their bodies besides their appendages. Walruses have whiskers to assist them really feel around on the ocean flooring. They have comparatively small eyes as a result of they rely primarily on the sense of contact to search out meals.

They have quick front flippers not solely to swim but additionally to help them on land. It makes use of its hind flippers as a motor to maneuver its giant body by the waters with the assistance of the front flippers to navigate which path it would go in.

Male Pacific Walrus has a higher mass than females, weighing as much as 1200 to 1500 kg, and could be as long as 320 cm. Females of the same age can weigh 600 to 850 kg and develop to a size of 270 cm. Males even have longer and thicker tusks than females. Males normally have thicker pores and skin than females as nicely.

Range and Habitat

Walruses inhabit areas within the Arctic that might be largely made up of ice. Walruses want areas with shallow water to allow them to simply access meals. This slow-moving marine mammal spends the vast majority of its time in or around water. Females spend more time on the ice versus males, who spend more of their time on sand or boulder seashores.

Pacific walrus migrates north in the course of the summer and south in the winter. The migrations are sure that the walruses could be the place probably the most optimum ice is discovered. Optimal is outlined as comparatively skinny ice however thick sufficient to carry the large weight of their our bodies.

Pacific walruses range over the comparatively shallow waters of the northern Bering and Chukchi seas and are sometimes noticed within the waters of the Eastern Siberian and Beaufort seas.

In the Bering Sea, walruses are distributed from the Bering Strait to Bristol Bay within the east, and within the west, their range extends as far south because of the Kamchatka Peninsula. They additionally use island haulouts close to St. Lawrence Island and on the Pribilof Islands.

Pacific walrus Food Habits

Walruses primarily feed on small invertebrates, mostly consuming bivalve mollusks. It is unknown precisely how walruses discover them. nonetheless, it’s identified that walruses use their hind fins to propel them ahead, whereas their tusks, mouth, and whiskers drag the underside of the ocean flooring in quest of meals.

Once the walrus has obtained a mollusk, it makes use of a suction methodology to ingest the within after its mouth and tongue have opened the shell. Occasionally a unique methodology is used to get shellfish open by crushing them open with their rounded teeth.

Due to the walrus’s diet of small organisms, giant portions are required to maintain them. Each time a walrus dives right down to eat, it might probably eat as much as 60 clams.

Their dives for meals normally final 5 to 20 minutes. Walruses can dive to depths of roughly 70 m. Adults require 25 kg of small benthic organisms per day. Walruses sometimes eat larger animals resembling seals and a few seabirds.

Pacific walrus eats all kinds of soppy invertebrates discovered on or beneath the seafloor through the use of their delicate whiskers to seek prey. Prey objects embody clams, snails, worms, sea cucumbers, and tunicates.

Except for his or her tusks, walrus teeth are flat; in consequence, walruses eat by sucking meals into their mouths utilizing the highly effective suction created by pulling their piston-like tongue back rapidly.

Pacific walrus sucks out the comfortable elements of clams and snails leaving the shells to fall to the seafloor. Some walruses, principally males, are identified to sometimes prey on seals and seabirds.

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Pacific walrus Behavior

Walruses dwell in a hierarchal system primarily based on age, body size, and tusk size. The older and stronger the walrus, the higher up it will likely be within the hierarchy.

The male Pacific walrus sets up dominance and compete for females by combating with its tusks. The tusk combating takes place whereas the walruses are at haul-out sites, which are normally rocky or sandy seashores close to the water. The walruses go to those haul-out sites to relax and sleep. Walruses can transfer the quickest whereas within the water.

Pacific walrus is social and spends most of its time with different walruses of the same sex. Female walruses keep in a single herd, whereas males keep in one other herd till breeding time.

Sometimes the packs can range from a whole bunch to hundreds. In the winter and summer, men and women come collectively in giant teams and get very shut to one another typically even piling on top of one another.

Walruses are extremely social animals that travel and rest in giant teams. The mom/calf bond, which lasts for roughly two years, is the longest and strongest amongst pinnipeds. Female walruses are identified to turn out to be dangerously aggressive if their calf is threatened.

When sea ice isn’t obtainable, walruses will generally rest on rocks, sandy seashores, and even grassy hills. Resting on land permits walruses the chance to type giant social haulouts that may include tens of hundreds of people.

Pacific walrus uses their tusks to assist pull themselves onto rocks or ice, maneuver ice to create a gap to dive by, and fight off predators.

The most typical use of tusks is social. Females will threaten and jab one another for a greater place on haulouts and in the course of the breeding season, male walruses will threaten and combat with their tusks to compete for females.

When two males come collectively, they’ll elevate and switch their heads sideways to display their tusks, and the walrus with smaller tusks will transfer away.

If the 2 males have similar-sized tusks, they’ll normally combat and will stab one another with their tusks, inflicting bruises and punctures. Walruses don’t use their tusks for digging on the seafloor for meals.

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Migration

The Pacific walrus inhabitants spend the winter on the Bering Sea pack ice before separating within the spring. Beginning within the spring, females with younger migrate northward from the Bering Sea to the Chukchi Sea, usually passively shifting with the receding sea ice.

Most adult males migrate to Bristol Bay the place they relax on land haulouts between foraging bouts. By late fall, walruses start their return migration southward from the Chukchi Sea to the Bering Sea, forward of the advancing sea ice.

The males that remained in Bristol Bay head north to fulfill the returning inhabitants within the waters close to St. Lawrence Island.

Lifespan

The average lifespan for walruses is between 30 to 40 years within the wild. They have a high survival charge as calves as a result of safety by the females. Lower life spans could also be a result of poachers and hunters.

In captivity, walruses have been recorded to dwell as much as age 30. However, ingesting objects that aren’t meant for consuming and tusk an infection may stop a long lifespan in captivity. Also, since they’re in an artificial environment, the behavior between moms and calves could trigger issues, resembling malnutrition.

Pacific walrus Communication

Walruses have small eyes which might be tailored to the chilly surroundings. Some fat cells are in place to assist maintain the eye’s heat. Some research points out that walruses can see in color, however, the range of the color spectrum is unknown.

Pacific walrus has a short-range vision and infrequently can not see when they’re on the ocean flooring scavenging for meals. The whiskers, additionally known as vibrissae, are used for feeling their method across the ocean flooring.

Pacific walrus uses its whiskers to assist establish meals or some other small objects. They can hear comparatively nicely on land however underwater, they use a system of tissue conduction to listen to.

This system closes their auditory meatus and solely permits them to listen to their outer ear tube. Walruses are vocal mammals. They talk throughout the mating season after they have mom and calf interactions, and when establishing dominance amongst different walruses. Walruses have a sequence of grunts and barks they’ll use within the conditions described above.

The Atlantic walrus and the Pacific walrus have barely completely different vocalizations. A research confirmed that walruses may differentiate between the 2 completely different subspecies vocalizations.

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Pacific walrus Reproduction

Walruses are polygynous, meaning that one male normally mates with many females. Males have many mating calls and noises they make to draw females throughout the mating season and as a way to mark their territory.

Underwater, the males make bell whistling noises and thumping noises to get the eye of females. These noises, not solely appeal to females but additionally function as a warning to different male walruses.

These noises are supposed to intimidate different walruses. When it involves mating, normally the strongest, largest, and oldest of the males get to mate with the females.

Tusk fights happen between males over who will get to mate with a gaggle of females both on land or in water. Sometimes these fights could be very ugly and even deadly.

Female walruses sexually mature between the ages of 5 and seven. Males sexually mature around ages 7 and 10 however don’t mate till they’re roughly 15 years old when they’re socially mature.

During the winter and summer, each female and male walruses collect within the hundreds to breed. Both sexes congregate of their haul-out sites, that are rocky or sandy seashores, to choose potential mates.

However, mating is believed to happen within the water. Walruses produce offspring most of their lives. Females produce one calf every three years. The average gestation interval for a feminine walrus is 15 months, which features a four to a 5-month delay within the egg implantation.

Because Pacific walrus breeds between January and April, the newborn walruses can be born the next year between April and June. The average weight of a walrus pup is about 60 kg with a size of 120 cm.

When the calves are born, they instantly know how one can swim. This, together with the mom’s safety, decreases the prospect for predation. Before the calves are weaned, they dwell with the herd of feminine walruses.

They are very dependent on their moms for the first few years. At age two, they are taught to scavenge for their very own meals and by age three, they’re utterly weaned. At this time, male walruses be a part of the male herd and females keep within the feminine group however are unbiased of their moms.

Female Pacific walrus starts breeding at 6-7 years of age and customarily gives start every 2 years. Males are mature at 8-10 years of age, however usually can not efficiently compete in opposition to older, bigger males for females till they’re 15 years old.

Walruses could dwell as much as 40 years. Unlike the opposite Alaskan pinnipeds, walruses mate within the water in the course of the winter months (January-March).

However, delayed implantation of the fertilized egg is suspended from additional growth for a number of months, leading to a total gestation interval of 15 months, the longest of all of the pinnipeds.

Pacific walrus calves are born on ice floes in late spring and weigh roughly 140 pounds. Calves sometimes stick with their moms for 2 years and weigh roughly 750 pounds after they turn out to be unbiased.

Pacific walrus Population

A 2006 aerial survey, carried out by the U.S. Fish and Wildlife Service (USFWS), estimated the inhabitants at 129,000, however as a result of difficulties in counting walruses the boldness of that estimate is low and the possible range in inhabitants size is someplace between 55,000 and 507,000.

After reviewing obtainable scientific and business information, the USFWS discovered that itemizing the Pacific walrus as threatened was warranted due to the lower sea ice brought on by local weather warming.

Currently, nonetheless, the itemizing is precluded by higher precedence actions to checklist different species. The USFWS will develop a proposed rule to checklist the Pacific Walrus as their priorities enable and can make any dedication to essential habitat in the course of the growth of the proposed itemizing rule.

To be taught more, go to the ADF&G Special Status web page for Pacific walrus.

Threats

Potential threats to the Pacific walrus inhabitants embody a discount in sea ice, predation by killer whales and polar bears, and if the site visitors of huge vessels will increase there might be threats from air pollution, ship strikes, and entanglement within the trash.

Specifically, the latest adjustments within the thickness and period of sea ice could have an effect on walrus distribution and feeding alternatives as much less ice is on the market.

Walruses use sea ice as a stable but drifting, a platform for resting between foraging journeys, calving, and touring. With much less sea ice, walruses will probably spend more time onshore haulouts alongside the Russian and Alaskan coasts the place foraging journeys could also be more restricted to foraging grounds close by.

Calves and yearlings endure elevated mortality on terrestrial haulouts when disturbances trigger the herd to panic and rush to the water operating over and crushing the smaller animals.

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Quick 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 dwell on and beneath the seafloor – clams, snails, soft-shelled crabs, shrimp, worms, sea cucumbers; sometimes seals and seabirds.
Predators
Polar bears, killer whales, and Alaska Native hunters
Reproduction
One calf is born each 2 years

Conservation

According to the IUCN Redlist of threatened species, walrus conservation standing is presently listed as knowledge poor. Walruses are threatened by hunters who use them for his or her bones, skin, and tusks.

According to IUCN red checklist, there are laws on walrus looking in Canada, Greenland, and the Russian Federation. In Alaska, most natives use walruses in a non-wasteful method. Walruses are absolutely protected in Svalbard and the Russian Atlantic underneath the North Atlantic Marine Mammal Commission.

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