stage oftheanimal. upon thenutritional stateandlifehistory greatly depending its thicknesscan vary storage. Blubberisadynamic tissueand and playsanimportantrole inenergy layer inthecoldmarineenvironment asanefficientinsulation Blubber serves Special Adaptations until theyare15to16yearsofage. and weighingasmuch4,000pounds, full adultbodysize,10to12feetinlength than females.Theyusuallydonotreacha faster andforalongerperiodoftime 10 yearsofage.Malestendtogrow a maximumbodysizebyapproximately declinesrapidlyandtheyreach walruses years oflife,thegrowthratefemale 1,200 to2,500pounds.Afterthefirstfew to 10feetandweighapproximately Adult femalescanreachlengthsofup tusks. tend tohavemoremassiveskullsand 50% heavierthanfemales.Malesalso Males areapproximately20%longerand Walrus animals. arelargeandpowerful Appearance the ice-freeseason. coastal hauloutsintheBeringSeaduring animals, primarilyadultmales,use Chukchi Sea;howeverseveralthousand summer monthsinthepack-iceof areas. Mostofthepopulationspends and forpassivetransporttonewfeeding calves, resting,isolationfrompredators, floating seaiceforbirthingandnursing ice-dependent speciesbecauseituses and iceconditions.Itisconsideredan seasonally andislimitedbywaterdepth Pacific distributionvaries walrus United StatesandRussia. boundariesofthe across theinternational arctic seas.ThePacific populationranges perimeter oftheArcticOceanandsub- Hemispherealongthe in theNorthern as “tooth-walkingseahorse”,arefound Walruses, whoseLatinnametranslates Pacific Walrus with each lie other; on young top often of the adults. haulout onto ice or land in groups. Walrus prefer to lie in close physical contact Walrus are extremely social and gregarious animals. They tend to travel and feeding dives last between5and10 to thebottom nearlycontinuously. Most to severaldays, duringwhichtheydive foraging bouts.Feeding tripscanlastup out onlandoricefloestorest between items. Walrus feedintermittently, hauling important thanvisioninlocating food sensitivity oftheirwhiskers maybemore and inmurkywater, suggestingthatthe stomachs.Walrus frequentlyfeedatnight arealsofrequentlyfoundintheir worms sea cucumbers,crabs,andsegmented however, otherinvertebratessuchas (clams) aretheirmostcommonfood; (ocean bottom)feeders.Bivalvemollusks Walruses arehighlyspecializedbenthic Feeding Habits animal ofcomparablesize. to threetimeslargerthanaterrestrial bloodvolume;uptotwo have anenormous muscles. Duetothisadaptation,they storeoxygenintheirbloodand walrus Like mostdivingmarinemammals, Odobenus rosemarus divergens U.S. Fish&WildlifeService after breedingoccurs, and thefetus after inlateJune,three tofourmonths uterus implantsinthe broken ice.The embryo throughMarch,inareasof January Breeding occursinlatewinter, from breeding occurs. join acourtingmaleinthewater where Individual femalesleavetheherdto visual andacousticdisplaysinthewater. elaborate the females,andperform males competeforchoiceareasnear maturity at15to16yearsofage.Adult usually mate until they reach full physical at 5to7yearsofage;howeverdonot becomefertile of age.Malewalruses reproductive potentialat4to9years reproduction. Mostfemalesattainfull to 40yearsormore,withlowratesof Walruses arelonglivedanimals,up Reproduction of1to2minutes. interval minutes, witharelativelyshortsurface

USFWS resumes development for eleven months. of 129,000 walruses. Calves are usually born in late April or May. Conservation and Management Pacific walruses are an important To compensate for their low reproductive subsistence resource in Alaska and rate, walruses have relatively low rates of Chukotka. Since the 1960s, U.S./Russia natural mortality. The mother-calf bond harvest levels have ranged from 3,200 to is extremely strong; the calf normally 16,000 animals/year. Population research, remains in her care for at least 2 years, harvest monitoring programs, local sometimes longer if not replaced by management efforts, and international

a new calf. A mother walrus is very coordination are necessary to ensure that USFWS protective of her new-born calf and will harvest levels remain sustainable. Adult female hauled out on sea ice defend it with vigor. The U.S. Fish and Wildlife Service with her calf. and Eskimo Walrus Commission waters where walrus feed and the number Population Trends work together to address subsistence of walruses using coastal resting areas has The current size and trend of the Pacific harvest issues in Alaska through a formal increased. Local management programs walrus population is unknown. Previous co-management agreement, and and conservation initiatives are going to efforts to estimate abundance have coordinate with Russian scientists and become increasingly important for the met with limited success because the subsistence user groups to monitor co-existence of walruses and humans population is distributed over such a subsistence walrus harvests in Chukotka. along the Arctic coast. large and generally inaccessible area. For more information, contact: A joint U.S./Russia aerial survey was Observed and projected trends of conducted in April, 2006. Thermal diminishing sea ice habitat over shallow U.S. Fish and Wildlife Service, Alaska infrared scanners were used to detect continental shelf waters and the expansion 1011 E. Tudor Road, MS-341 walruses resting on pack ice in the of commercial activities into the Arctic Anchorage, Alaska 99503 Bering Sea. Satellite telemetry tags present significant conservation and 907/786 3800 or 800/362 5148 were used to account for diving animals management challenges for this species. In http://alaska.fws.gov not detected by scanners. Survey efforts recent years, summer sea ice has retreated produced a minimum population estimate beyond the shallow continental shelf January 2011