the state and future of mammal populations in the …the state and future of mammal populations in...
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The State and Future of Mammal Populations in The State and Future of Mammal Populations in the Beaufort Sea and Arctic Oceanthe Beaufort Sea and Arctic Ocean
Polar Bears and Walrus as Sentinels ofPolar Bears and Walrus as Sentinels ofPolar Bears and Walrus as Sentinels of Polar Bears and Walrus as Sentinels of Arctic ChangeArctic Change
Dan James, Chad Jay, Steven Amstrup, and Dave DouglasDan James, Chad Jay, Steven Amstrup, and Dave Douglas, y, p, g, y, p, gU.S. Geological SurveyU.S. Geological Survey
U.S. Department of the InteriorU.S. Geological Survey
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Habitat LossHabitat LossIndustryIndustrySubsistenceSubsistence
TourismTourism
Why polar bears and walrus?y pArctic undergoing rapid change
Both species are symbols of the Arctic
Both species integrate change at lower trophic levels
Both species tightly tied to sea ice – proxies for the status of the arctic ecosystem
Lif Hi tLife History
Atlantic
Pacific walrus
(90% of the
Atlantic walrus
(90% of the world
population)
G l Bi lGeneral Biology
General Biology ...
Life HistoryLife History
RANGE OF POLAR BEARSIN THE POLAR BASIN
RUSSIAIN THE POLAR BASIN
GREENLANDNORTHNORTH POLE
CANADAALASKA
U.S.A
Polar Bears Polar Bears Utilize three Utilize three Ecological Ecological ggStrategiesStrategies
Life history dependence on sea iceLife history dependence on sea ice
••ForagingForaging
••ReproductionReproductionpp
Like all bears, polar bears begin life very small.Like all bears, polar bears begin life very small.
••Females can weigh 800 pounds and males 1400 pounds Females can weigh 800 pounds and males 1400 pounds
P l b li f 30P l b li f 30••Polar bears live for 30 years.Polar bears live for 30 years.
••There are 22,000 There are 22,000 -- 25,000 polar bears in the Arctic.25,000 polar bears in the Arctic.
DiatomsDiatoms
PolarPolarPolarPolarbearbear
ArcticArcticf d h if d h ifood chainfood chain
CopepodsCopepodsArctic codArctic cod
Ringed sealRinged seal
CopepodsCopepods
Research ChallengesResearch Challengesgg
I d t 80% f tiI d t 80% f ti Live on surfaceLive on surfaceIn or under water 80% of timeIn or under water 80% of time Live on surfaceLive on surface
Research ChallengesResearch Challengesgg
t 1997*
Can
ice extent 16 Sept. 1997
Beaufort Sea
Chukchi
Males to land
Russia Alaska Sea
Bering Sea
Females stay with ice
ice extent11 March1997*
WALRUSWALRUSLarge, segregated migrationsLarge, segregated migrations
POLAR BEARSPOLAR BEARSMixed populationsMixed populations
*Source: National I
g , g g gg , g g g p pp p
Research ChallengesResearch Challengesgg
Harder to capture Harder to capture or handleor handle
Easier to capture Easier to capture or handleor handle
Sea Ice, Arctic Climate, andSea Ice, Arctic Climate, andSea Ice, Arctic Climate, and Sea Ice, Arctic Climate, and Wildlife HabitatWildlife Habitat
Al k S i C tU.S. Department of the InteriorU.S. Geological Survey
Alaska Science Center
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