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
Conservationists may be miscalculating the numbers of the threatened animals such as elephants, say African and American rese
Conservationists may be miscalculating the numbers of the threatened animals such as elephants, say African and American rese
admin
2010-11-02
78
问题
Conservationists 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 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 aeroplanes is impossible in the vast, equatorial 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 tallying elephants in one region tend to rely on standard decay rate 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 to the census astray, says Plumptre.
He and his colleague Anthony Chifu Nchanji studied decaying elephant dung in the forests of Banyang-Mbo Wildlife Sanctuary in southwest Cameroon. They found that the dung decayed between 55 and 65 percent more slowly than dung in the rainforests of neighboring 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 at least twice as high as those derived from decay rates calculated locally, says Plumptre. "However accurate your dung density estimate, 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 outside."
Plumptre says that similar problems may also plague other animal census studies that rely on indirect evidence such as nests, tracks or burrows.
The word "threatened" in the first sentence of the first paragraph could be best replaced by______.
选项
A、endangered
B、frightened
C、died
D、angered
答案
A
解析
词语释义题。应该从全文的角度来理解threatened这个词,通篇讲述的内容与环保有关,作者又把大象作为一个典型的例子加以说明,根据各种数据我们了解到大象是一个濒危物种,所以答案是A。
转载请注明原文地址:https://kaotiyun.com/show/SPs7777K
0
大学英语六级
相关试题推荐
A、Ahousepainter.B、Amailman.C、Herneighbor.D、Herhusband.A
A、Becausenearly1,000millionacresoflandwasburnedoff.B、Becausenaturalresourcesarebeingusedup.C、Becauseanimalsan
A、Thewomanisupsetbecauseshedidn’tpasstheexamination.B、Thewomandoesn’thopeforapromotion....C、Themangetsused
TodayAmericanparentsarefindingthemselvesina【B1】______abouthowtodealwithteenagedrinking,aserioussocialproblem.
A、Mood.B、Tiredness.C、Carelessness.D、Weather.D选项和因素有关。本题是细节题。从leadinguptothemisfortune—frustration,tiredness,orjustba
A、Findafamiliarface.B、Findakindperson.C、Starttalkingwithastranger.D、Squeezeintotheline.A本题是细节题。从Oneofthemore
A、At6:15.B、At5:50.C、At16:05.D、At16:15.D综合推断题。女士说shouldhavetakenoffat14:00,用的是虚拟语气,表明飞机并没有在14:00起飞,结合后面的groundedfor
High-speedtrainsareoftenthefastestwaytotravelbetweencitycentersinEurope,beatingshort-haulflightsforjourneysof
High-speedtrainsareoftenthefastestwaytotravelbetweencitycentersinEurope,beatingshort-haulflightsforjourneysof
随机试题
化疗药物可通过()、()、()等途径,对经常接触的护士带来一定的潜在危害。
评价血涂片的质量时应考虑
《招标师注册执业管理办法》规定,注册有效期满需继续执业的,应在注册有效期满前()个月内申请延续注册。
已知f(x)是二阶可导的函数,y=e2f(x),则为()。
金融企业应在每批次不良资产转让工作结束后()个工作日内,向同级财政部门和中国银监会或属地银监局报告转让方案及处置结果。
小说集《十日谈》的作者是()。
Inthe1950s,thepioneersofartificialintelligence(AI)predictedthat,bytheendofthiscentury,computerswouldbeconver
吴敬梓是哪本名著的作者()。
历史的真实不等于真实的历史。鲁迅说《史记》是“史家之绝唱,无韵之离骚”。好的史学作品必须突破那层僵化的历史真实观,直接触及历史人物的灵魂,写出历史的本质真实来。以下哪一项是上述论证所依赖的假设?
Sincethepre-historictimes,manhashadanurgetosatisfyhisneeds.Beithunger,shelterorsearchforamate,hehasalway
最新回复
(
0
)