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1、智课网TOEFL备考资料候鸟被迫迁徙更远一托福阅读机经背景Climatechangewillforcebone-wearybirdsmigratingtoEuropefromAfricatologextramileage,withpossiblydevastatingconsequences,accordingtoastudyreleasedonWednesday.Theannualvoyageofsomespecies,whichflynorthinsearchoffoodandsuitableclimes,couldincreasebyasmu
2、chas400kilometres(250miles),theresearchfound."Marathonmigrationsforsomebirdsaresettobecomeevenlonger,"saidStephenWillis,aprofessoratDurhamUniversityinBritainandthemainarchitectofthestudy."ThisisbadnewsforbirdsliketheWhitethroat,acommonfarmlandbird.Theaddeddistanceisaconsiderab
3、lethreat."Astemperaturesriseandhabitatschange,birdswillfacetheirbiggestchallengesincethePleistoceneera,whichended11,000yearsago”,hesaidinastatement.Some500millionbirdsmigrateeachyearfromAfrica,someweighingaslittleasninegrammes(three-tenthsofanounce).Tocompleteavoyagethatcanbet
4、housandsofkilometreslong,birdshavetofattenthemselvesuptotwicetheirnormalweight.Someevenshrinktheirinternalorganstobecomemorefuelefficient,soanyadditionaldistancetravelledtakesitstoll.ThestudyispublishedintheJournalofBiogeography.From2071to2100,nineoutof17speciesexaminedareproj
5、ectedtofacelongermigrations,particularlybirdsthatcrosstheSaharadesert,thestudyfound.SomebirdstraversetheSaharaandtheMediterraneanSeainaonego,whileothersmakeapit-stopinnorthernAfricabeforecrossing.Manyflyatnight,whentemperaturesarecooler.Afew--suchastheBlackcap--havestartedtoad
6、aptbyspendingwintersinBritain,butsuchbehaviourremainsexceptional,thestudysaid.ThestudyforecastthatthemigrationdistanceoftheOrpheanWarblerwilljumpfrom2,700kilometres(1,700miles)tobetween3,050and3,350kilometres(1,900and2100miles),withevenlongerincreasesfortheSubalpineandBarredWa
7、rblers本周三公布的一项研究显示，气候变化将迫使从非洲迁徙至欧洲的候鸟再多飞数百英里，对于已经精疲力尽的鸟来说，这可能会带来毁灭性的后果。研究发现，一些向北飞行以觅食和寻找合适栖息地的候鸟每年飞行的距离可增加约400公里(合250英里)。英国达翰姆大学的教授、研究骨干斯蒂芬•威利斯说：“对于一些候鸟来说，马拉松式的迁徙路程将变得更远。”“这对白喉莺这样的普通农田鸟类来说是个坏消息，多飞的行程对于它们来说是个很大的威胁。”他在一份声明中称：“随着温度上升，栖息地环境变化，候鸟将面临自1.1万年前结束的更新世(译者注：属于或标志第四纪的两个时期中较
8、早时代的地质时期、岩石系列和沉积矿床的，这一时期以互生外貌、北方冰蚀退缩和人类祖先的出现为特征)时期以来最大的挑战。”每年
