首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Don’t Count on Dung "Conservationists(自然保护主义者)may be miscalculating the numbers of the threatened animals such as elephants,
Don’t Count on Dung "Conservationists(自然保护主义者)may be miscalculating the numbers of the threatened animals such as elephants,
admin
2011-01-22
28
问题
Don’t Count on Dung
"Conservationists(自然保护主义者)may be miscalculating the numbers of the threatened animals such as elephants, " say African and American researchers. The error occurs because of a flaw in the way they estimate animal numbers from the piles of dung(粪)the creatures leave behind.
The mistake could lead researchers to think that there are twice as many elephants as there really are in some regions according to Andrew Plumptre of the Wildlife Conservation Society(WCS) in New York.
Biologist Katy Payne of Cornell University in Ithaca, New York, agrees. "We really need to know elephant numbers and the evidence that we have is quite indirect, "says Payne, who electronically tracks elephants Counting elephants from planes is impossible in the vast rainforests of Central Africa. So researchers often estimate elephant numbers by counting dung piles in a given area. They also need to know the rate at which dung decays because it’s extremely difficult to determine these rates. However, researchers counting elephants in one region tend to rely on standard decay rates established elsewhere.
"But researchers at the WCS have found that this decay rate varies from region to region depending on the climate and environment. Using the wrong values can lead the census astray(离开正道)," says Plumptre.
He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Cameroon. They found that the dung decayed between 55 and 65 per cent more slowly than the dung in the rainforests of neighbouring Gabon. If researchers use decay rates from Gabon to count elephants in Cameroon, they would probably find more elephants than are actually around.
"This could mean estimates in Cameroon are at least twice as high as those derived from decay rates calculated locally," says Plumptre "However accurate your dung density estimate might be the decay rate can severely affect the result."
Plumptre also says that the dung-pile census should be carried out over a region similar in size to an elephant’s natural range. The usual technique of monitoring only small, protected areas distorts numbers because elephants move in and out of these regions, he says" If the elephant population increases within the protected area, you can not determine whether it is a real increase or whether it is due to elephants moving in because they are being poached(入侵偷猎)outside. "
Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests, tracks or burrows(地洞).
Why do researchers estimate elephant numbers in an area by counting dung piles?
选项
A、Because elephants are difficult to catch.
B、Because it is not possible to count elephants from a plane.
C、Because it is not possible to keep track of elephants.
D、Because elephants are shy animals.
答案
B
解析
第三段有这么一个句子,意思是说:从飞机上数中非广阔的赤道雨林中的象是不可能的,研究人员通过数粪堆估计一个特定地区的粪堆来估计该区域的象数,故选B。
转载请注明原文地址:https://jikaoti.com/ti/0dNsFFFM
本试题收录于:
职称英语综合类A级题库职称英语分类
0
职称英语综合类A级
职称英语
相关试题推荐
TheGreatNewspaperWarUpuntilabout100yearsago,newspapersintheUnitedStatesappealedonlytothemostseriousread
PodcastRecentlyagroupofsecond-gradersvisitedourschoollibrarytoworkona"holidaysaroundtheworld"project.The
FalseFearofBigFishManypeoplebelievesharks(鲨鱼)aredangerousandwillalwaystrytohurtorevenkillhumans.【B1】____
LongerLivesforWildElephantsMostpeoplethinkofzoosassafeplacesforanimals,wherestrugglessuchasdifficultyfin
PlantsinDesertOnlyspecialplantscansurvivetheterribleclimateofadesert,fortheseareregionswheretheannualra
MusicalTrainingCanImproveCommunicationSkillsAmericanscientistssaymusicaltrainingseemstoimprovecommunicationsk
FewFactsaboutSingapore1.SingaporeisanindependentcitystateinsoutheasternAsia,consistingofonemajorisland—the
EarthAngels1.JoyingBresciawas8yearsoldwhenshenoticedthatcigarettebutts(烟头)werelitteringherhometownbeachin
WhentoTakeMedicineIsImportantOurbodiesarewonderfullyskillfulatmaintainingbalance.Whenthetemperaturejumps,
VoltsfromtheSky1.Lightninghascausedaweandwondersinceoldtimes.AlthoughBenjaminFranklindemonstratedlightninga
随机试题
王某,女,80岁,30年前患慢支。现症咳逆喘促日重,咳痰不爽,表情淡漠,嗜睡,甚或意识艨胧,谵妄,烦躁不安,入夜尤甚,昏迷,撮空理线,或肢体瞤动,抽搐,舌质暗红或淡紫,或紫绛,苔白腻或黄腻,脉细滑数。本病例诊断为
一新生儿患Rh溶血病,以下哪种情况不会出现
纳税人陈某因涉嫌逃避缴纳税款被有关机关立案侦查,并被依法逮捕。下列说法中正确的有()。
增值税一般纳税人发生的下列情形中,应视同销售计算增值税销项税额的是()。
电信业务经营者取得经营许可证后,应当在()内或者电信业务经营许可证特别规定的时限内,按照电信业务经营许可证规定的业务种类和业务覆盖范围提供电信服务。
园林花木中被人们称为“四君子”的是()。
1864年江海关道丁日昌密查:“内地商人买雇洋商火轮夹板船只,写立笔据,多托洋行出面,赴领事衙门呈报更名人册,领取船牌行驶,从未赴地方官报明立案。”这种现象产生的主要原因是()。
2017年是香港回归祖国20周年,香港特别行政区的区花是:
著作权全部权利内容的保护期为作者终生及其死后50年。()
执行SQL语句DROPVIEWMyView的结果是( )。
最新回复
(
0
)