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 researc
Conservationists may be miscalculating the numbers of the threatened animals such as elephants, say African and American researc
admin
2013-07-01
70
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.
All of the following are indirect evidence EXCEPT______.
选项
A、trunks
B、dung
C、nests
D、burrows
答案
A
解析
细节题。这道题的答案可以在最后一段中找到Plumptre says that similar problems may also plagueother animal census studies that rely on indirect evidence such as nests,tracks or burrows.(Plumptre认为同样的问题也可能困扰其他的动物数量普查,这些普查很大程度上依赖类似动物的窝。走过的踪迹,还有住过的地洞等等。)很显然答案是A。
转载请注明原文地址:https://kaotiyun.com/show/p8n7777K
0
大学英语六级
相关试题推荐
Agricultureisundoubtedlythemostimportantsectorintheeconomiesofmostnon-oilexportingAfricancountries.It【C1】______
Theround-the-clockavailabilitythatcellphoneandpagershave【C1】______topeople’slivesmaybetakingatollonfamilylife
Somestudentsarenotadequatelypreparedforcollege.Shouldweturnthemaway?【B1】______them?Ormodifyourproduct?Americ
A、Byahill.B、Aconcert.C、Thewaterfallscenery.D、Ahoteltheyoncestayedin.D本题问“根据对话内容,他们要去哪直度周末”。如文中反复提到的“WatermillInn”
A、Makingafactualrecordofdetails.B、Capturinghersubject’spersonality.C、Beautifulcompositionofapicture.D、Lighteffec
By2020cancerratesworldwide______(可能会增加百分之五十).
A、Sheisselfishandcruel.B、Sheiskindandpolite.C、Sheisproudandhelpful.D、Sheislonelyandunhappy.A短文中举了一个反例,即McGar
A、Thenumberofteachershasdecreased.B、Thequalityofhighereducationhasdeclined.C、Thehighereducationhasexpandedmass
Commutertrainsareoftenstuffyandcrowded,andtheyfrequentlyfailtorunontime.Asifthatwerenotbadenough,Tsuyoshi
Itwasnotuntil______(你告诉我我才知道问题的解决方案在讨论中).
随机试题
氨基糖苷类抗生素能与细菌核糖体的30S基结合,抑制细菌蛋白质的合成。
格迪斯和芒福德与区域规划理论的关系?
如果企业银行存款日记账余额与银行对账单余额相等,则说明不存在未达账项。()
财政部门实施会计监督检查的对象是经济活动。()
甲、乙、丙、丁以合伙企业形式开了一家普通合伙企业。就该合伙企业事务的执行,下列选项表述正确的有()。
联机系统,是指集装箱出租公司将其用于集装箱运输管理的计算机中心与设置在有关各港代理处的终端机联网,使集装箱的各种动态信息随时可显示出来,或者根据需要可直接打印从计算机中心传输来的各种处理结果或其他有关信息。()
陶行知教育思想的核心是()
statutorylaw
在一台主机上用浏览器无法访问到域名www.online.tj.cn的网站,并且在这台主机上执行tracert命令时有如下信息分析以上信息,会造成这种现象的原因是()。
关系数据库管理系统能实现的专门关系运算是
最新回复
(
0
)