Dont Count on Dung
Conservationistsmay 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 dungthe creatures leave behind.
The mistake could 1ead 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 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 indirectsays 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 its 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,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 PlumptreHowever accurate your dung density estimate might be.the decay rate can severely affect the result
Plumptre also says that the dungpile census should be carried out over a region similar in size to an elephants natural range The usual technique of monitoring only small,protected areas distorts numbers because elephants move in and out of these regions,he saysIf the elephant population increases within the protected area,you can not determine whether 1t is a real increase or whether it is due to elephants moving in because they are being poachedoutside.
Plumptre says that similar problems may also affect other animal census studies that rely on indirect evidence such as nests,tracks or burrows
1The wordthreatenedin the first sentence of the first paragraph could be best replaced by
A endangered
B frightened
C killed
D angered
2 Why do researchers estimate elephant numbers in an area by counting dung piles?
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
3 Piles of dung cant be relied upon when it comes to estimating elephant numbers because
A they are different in size
B they scatter an over the region.
C they are different in decay rate.
D they are different in quality.
4 According to Plumptre,the region over which a dungpile census is carried out should be
A small enough
B well protected.
C carefully monitored.
D large enough
5The first wordHein paragraph 6 refers to
A Andrew Plumptre
B Katy Payne.
C Anthony Chifu Nchanji.
D the writer of the article.
参考答案
1 A threatened:有灭绝危险的。threatened animals:有灭绝危险的动物。endangered:有灭绝危险的;有生命危险的。an endangered species:一个有灭绝危险的物种。frightened:受惊的。killed:杀死了的。angered:激怒了的。
2 B 该题问的是:为什么研究人员通过数粪堆估计一个地区的象数?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估计该区域的象数。因此B是正确答案。
3 c 该题问的是:不可依据粪堆数估计象数的原因是什么?文章第五段第一句话是这么说的:这种取决于气候和环境的腐烂速率在不同的地区是不一样的。可见c是正确的答案。A说的是:它们的大小是不一样的。B说的是:它们散布在整个地区。D说的是:它们的质量是不一样的。
4 D 该题问的是:根据Plumptre的观点,选择粪堆普查的地区应符合什么样的条件?倒数第二段提到了P1umDtre的观点,即普查的地区应该大到不能使象自由出入,也就是说,必须足够大。A说的是:足够小。B说的是:得到了很好的保护。c说的是:得到了密切的监控。
5 A 该题问的是?第六段的第一个词He指谁?一般情况下,代词回指的词必须离得很近。因此必定是Andrewr Pqumptre
2016考研英语高频考点解题技巧 "搭配记忆"法(五)
2016考研英语复习常见疑问解答
2015年考研复试面试经典60问提前看
经验分享:心境很重要!
2015考研复试考前指导 复试流程抢先知
考研英语75分另类复习法
春天如此美好,你却在见周公?
考研英语常用同义词辨析必读--F
2016考研英语高频考点解题技巧 "搭配记忆"法(三)
三招教英语“学渣”轻松过考研国家线
考研英语常用同义词辨析必读--C
2016考研英语高频考点解题技巧 "搭配记忆"法(二)
2015考研复试:复试英语
2016考研英语高频考点解题技巧 "搭配记忆"法(七)
2016考研英语高频考点解题技巧 "搭配记忆"法(十)
2016考研英语高频考点解题技巧 "搭配记忆"法(六)
2015考研复试:必备材料
考研英语常用同义词辨析必读--E
2015考研调剂八步 步步惊心
2016考研英语:新题型三大解题技巧get
2016考研英语高频考点解题技巧 "搭配记忆"法汇总
2015考研复试:复试会以怎样的姿态呈现
2015年考研复试 别因为这五件事out
2016考研英语语法精析:虚拟语气
探究学习路上的四大症结
四点搞定考研英语复试问答
备战考研:给考研新手的四大入门建议
2015考研调剂:调剂之门向谁开?
考研英语常用同义词辨析必读--A
考研英语常用同义词辨析必读--G
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |