Challenges Of Life文档格式.docx

Challenges Of Life文档格式.docx

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Thissortofadvantage

maymeanthedifferencebetweenlifeanddeath

inthesurvivalofthefittest.

Thisseriesrevealsthemostspectacularandextraordinary

strategiesthatanimalsandplantshavedevelopedtostayalive.

Foreverycreature,everydayisfullofchallenges,

allofwhichmustbeovercome,somehow,inordertosurvive.

Kenya,famousforitsbigcats.Thesupremehunters.

Cheetahsspecialiseinhuntingatspeed.

Thoughfast,theyarefragilecreatures,builttosprintaftersmallprey.

Theydon'

thavethestrengthorweightofalion

tobringdownlargeranimals.

Thismaleisdifferent.Hedoesn'

thuntalone.

He'

slearntthatthereisstrengthinnumbers.

Butheretherearenotjusttwo,butthreecheetahs.

Abandofbrothers.

Theyhavechangedtheirtacticsand,bydoingso,

havetakentheirpreybysurprise.

Theyhavelearntthatworkingtogether

theycanbringdownlargeprey.

Anostrich.

Abirdthattowersoveracheetahandismorethantwiceasheavy.

Itcan'

tflytoescapedanger,butitcanlashoutwithadeadlykick.

Afemale,unawareasyet,ofanydanger.

Evenwiththreeofthemthisisstillhighlyrisky.

Ifonegetsinjured

theothertwocouldn'

thopetotacklesuchlargeprey.

Ontheotherhand,

iftheygetitright,therewardsarehuge.

Themalehasspottedoneofthebrothers,butonlyone.

It'

snottooworried.

Thensuddenlytherearethree!

Thefemaleisslowertorealisethedanger

andthecheetahsswitchtargets.

Ittakesthecombinedeffortandweightofallthreebrothers

tobringdownthispowerfulbird.

Evennowtheostrichcouldlandafatalkick.

Sofar,thebrothersarewinning.

Ostricheshaveyettofindawaytofoilsuchtactics.

Otheranimalshavealsoevolvedsurprisingtacticstooutmanoeuvre

theenemy,notwithbrutestrength

butwithextraordinaryweapons.

Madagascar.

Astrangeworldwherenothingisquiteasitseems.

Tohunthererequiresstealthandsubterfuge.

Andlivingwithinthetreesisamasterofambush.

Apreyingmantis.

Wellcamouflagedandlightningquick,

theseinsectsarehighlyefficientpredators.

Buteventheyareoutgunned.

Achameleon.

Itscamouflageisexceptional

becauseitcanchangeitsskincolourtomatchitssurroundings.

Itseyesmoveindependentlytospotprey.

Itcreepstowardstoitsvictim,untiljustinrange.

Thenitunleashesasuperweapon.

Itstongueshootsoutat15metrespersecond.

Andnotonlyhits,butgraspsitstarget.

Butfewhuntersarealwayssuccessful.

Forthemahuntisjustonemeal.

Forprey,thestakesarehigher.

slife...ordeath.

AsAntarcticamovesfromspringintosummer

theinletsandbays,oncechokedwithice,becomefree.

Andanimalsmoveintofeed.

Thesearecrabeaterseals.Theydon'

tactuallyeatcrabs

butkrill,smallshrimpsthatswarmintheirbillionsinthesewaters.

Restingonalargeicefloe,

thesecrabeatersaresafe.

Butassoonastheyenterthewater,

theyareontheirguard,

forgoodreason.

Killerwhales.

HereinAntarctica,manykillerwhalespreyonlyonfish.

Butthesewhalesaredifferent,theyspecialiseinhuntingseals.

Thissealswimmingtoopenwater

isunawareofthedangerheadinghisway.

Untilnow.

sinrealtrouble.

Thereisnoescapeunlesshecanhidebehindthissmallpieceoffloatingice.

Buthe'

sbeenspottedandsurrounded.

Nowagilityishisonlychance.

Hedodgesforhislife,stayingascloseashecantotheiceberg.

stiring.

Andthewhalestightenthecircle,goingforthekill.

Buthuntersdon'

talwaysgettheirownway.

Intheend,theseal'

sdeterminationandskill,using

theiceforprotection,kepthimjustoutofreach.

Andthewhalesmoveon.

Recentlyit'

sbeenobservedthatkillerwhales

aremuchmoresuccessfulwhenhuntingothertypesofseal.

Crabeaterslikethisputuptoomuchofafight.

Forcreatureslivingintheopenocean

thereisnowheretohidefrompredators.

Butthereissafetyinnumbers.

Onefish,however,hasevolvedadifferentescapetactic.

Toleavethewatercompletely,taketotheairandfly!

Afterahugeefforttogetairborne,flyingfish

canglide200metresorso,

toescapethepredatorschasingthem.

Notallanimalsarehunters,manyarevegetarians.

Butthebattlebetweenanimalsandplants

canalsobeintense.

BoaVista,centralBrazil.

Thisvalleyispepperedwithstrangelypittedrocks.

Thesearenotnaturalformations

butthelegacyofalongstrugglebetweenoneanimalandoneplant.

Brown-tuftedcapuchins,highlyintelligentmonkeys.

Theyspendtheirnightsinthesafetyofcaves,

emergingeachmorningtofindfood.

Downinthevalleyisaparticularfavourite.

Anutpalm.

Thepalmsproducehugeseeds,

buttheyhaveverystrongshells

thatprotectthemagainstattackfromhungryanimals.

Forthecapuchinsthisisawarofattrition.

Theycheckwhichseedistheripest,

andthebattlecommences.

Thefirstjobistotearthetoughfibroushuskfromthenut.

Hedoesn'

ttrytocrackthenutstraightaway,

butdropsittotheground.

slearntthatanutshouldbegivenaweekorsodryinginthesun.

Theseareoneshepreparedearlier.

Hetapsthemtoseeifthey'

reready.

Thishugeflatrockishisanvil.

Andthisisahammer.

smadeofadifferentandmuchharderrockthantheanvil.

Nowsomethingextraordinaryhappens.

Thecapuchins'

useofthesestonetoolsrequiresanexceptionallevel

ofintelligence,planninganddexterity.

Thenutfinallycracks

andexposesarich,oilykernel.

Youngsterswatchandimitatetheadults,

justashumantoddlersdo.

Iftheyaretobecomeindependent,theymustlearntocracktheirownnuts.

Butthelearningprocessislong,withmanyfrustrations.

Theylearnearlyonthattodoajobproperly,

youneedtherighttool.

Itcantakeeightyearsforacapuchintomasterthisart

andovercomethepalm'

sformidabledefences.

Butsomeplantshaveturnedthetablesandfeedonanimals.

Thisisahighlysophisticatedtrap.Thebait,

sugarynectararoundtherimofthedisc.

Thetriggers,finehairs,

twoofwhichhavetobetouchedwithin20secondsofeachother.

Thevictim,afly

whichfindsthecolourandnectarirresistible.

Whentriggered,thetrapsnapsshutsofast

thattheflyisimprisoned.

TheVenusflytrapnowslowlydigestsitsvictim.

Life'

schallengesaremorethanjustfindingfood.

Ineveryanimal'

slifetherecomesatime

whenitsmindturnstobreeding.

Onecreature'

sapproachismind-boggling.

Malaysia.

Thisstrangeinsecthasbeenlyingdormantontheforestfloor.

Oncesafeinthetrees,

thesemaleshideamongtheleaves

andbeginanextraordinarytransformation.

Onethatwillmakethedifferencebetweenfatheringoffspringornot.

Hebeginsbygulpinginairbubbles,

forcingthemupintohishead.

Hethenpumpsthebubblesintothestalkssupportinghiseyes,

justlikeblowingupaballoon.

Andthisiswhatearnsthesecreaturestheirname,

thestalk-eyedfly.

Afewfinaladjustments

tostraightenoutanyremainingcreases

andhe'

sreadyforaction.

Theymaylookunwieldy,

buteyesonstalksimprovenotonlyhisabilitytospotpredators,

buttheyarekeywhenitcomestowinningfemales.

Intheeveningbothmalesandfemalesgather

andthemalesbegintosizeoneanotherup,

eyeballtoeyeball.

Havingthewidesteyespan

putsyouatthetopofthepeckingorder.

Theeyestalksarenotweapons,

they'

remeasuringsticks,usedtogauge

howbig,andsohowstrong,amaleis.

Butthere'

stroubleiftwotopmaleshaveexactlythesameeyewidth.

Thenthecontestdescendsintoabrawl.

Defeated.

Thewinner.

Henowhastherighttomatewithallthefemalesnearby.

Therathergentlemanlywaystalk-eyedflies

settletheirdifferencesoverfemales

isnottheonlyway.

Someanimalsaremuchmoreviolent.

sthedryseasoninZambia.

Thelagoonsareeitherbakeddry,

orthemudissothickanimalsgetstuck,

withfatalconsequences.

Thismalehippohasbeenlivinginonesmalllagoon,

butasitdries,it'

sturningintoadeathtrap.

Understandably,thefemalesthatonceshareditwithhimhaveallleft.

Evenifhewantsto,

hecan'

tstaymuchlonger.

Heneedswatertokeepcoolandfemalestomatewith.

Andthisiswheretheyallare.

Almostallthehipposinthearea

areinwhatisleftoftheLuangwaRiver,

becauseit'

sthelastplacewherethere'

sstilldeepwater.

Thisbendiscontrolledbyanall-powerfulmale.

Sincethedroughtmanymorefemaleshavejoinedhisherd.

Theyarehappytolivecheekbyjowl,

butanymalewhocomeshereinthehopeofmating

mustfirstdefeattheoverlord.

Thewanderingmalearrivesandhasadecisionto