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
66
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
Nooneshouldbeforcedtowearauniformunderanycircumstance.Uniformsaredemandingtothehumanspiritandtotallyunneces
UnitedStatesgovernment,andtheAmericanpeople.Itshistory,andthehistoryofthenation’scapital,beganwhenPresidentGe
Nooneshouldbeforcedtowearauniformunderanycircumstance.Uniformsaredemandingtothehumanspiritandtotallyunn
OnemajordecisionwhichfacestheAmericanstudentreadytobeginhighereducationisthechoiceofattendingalargeuniversit
Inthemedicalprofession,technologyisadvancingsofastthatquestionsoflawandethicscannotbediscussedandansweredfas
A、BecausesheistheassistanttoDr.Collin.B、Becauseshewantstoshowoffherself.C、BecauseshehasreadalotonDME.D、Be
A、Atascienceexhibit.B、Atanewsconference.C、Nearanartmuseum.D、Nearapaintstore.C选项都和地点有关。从goinandseethenewexh
A、Youshouldbelieveeverythingyouread.B、Shethinksthebookisexcellent.C、Shewonderswhichnewspaperhereads.D、Reaction
A、Tohaveanintimatetalkwithyou.B、Toknowyouasaperson.C、Toconfirmyourqualifications.D、Toknowmoreaboutyourfami
A、Hedislikesmuseumsandgalleries.B、Hedoesnotcareabouttheweather.C、Goingtothebeachisthebestchoice.D、Hedoesn’t
随机试题
A.球囊B.面神经C.听小骨D.半规管E.蜗螺旋管位于鼓室内的是
“桃红和青白色的杂花在眼前还明亮,到远处就成为斑斓的烟霭了”一句运用了________________的修辞手法。
心房颤动的临床特点包括
患者,男,52岁。阵发性心悸半年,时有胸闷,登2楼觉气急3个月,下肢水肿3天来院门诊。心电图示窦性心律,心率64次/分,PR间期0.24秒伴完全性右束支传导阻滞,诊断为扩张型心肌病,心功能不全。入院后予以洋地黄、利尿药和扩血管药物治疗。第4天突然神志不清,
患者,女性,33岁。大专文化,于今日自然分娩一女婴。在产后指导哺乳的措施中,正确的做法是
两套平面坐标系,在进行四参数坐标转换时,最少需要()个公共点。
抗冻等级()以上的混凝土简称抗冻混凝土。
在空气压缩机的进出风管适当位置安装消声器的做法,属于施工噪声控制技术中的()。
居住国政府对其居民在非居住国得到税收优惠的那部分所得税,视同已纳税额而给予抵免,不再按本国税法规定补征,这属于()。
张某与海河公司于2005年3月签订合同,约定张某以40万元向海河公司购买1辆大客车,合同签订之日起1个月内支付30万元,余款在2006年12月底前付清,并约定在张某付清全款之前该车所有权仍属海河公司。张某未经其妻同意,以自家住房(婚后购买,房产证登记所有人
最新回复
(
0
)