首页
登录
职称英语
Don’t count on dung Conservationists
Don’t count on dung Conservationists
资格题库
2022-08-02
53
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).文章(31~35)The word "threatened" in the first sentence of the first paragraph could be best replaced byA "endangered".B "frightened".C "killed".D "angered".
选项
A "endangered".
B "frightened".
C "killed".
D "angered".
答案
A
解析
转载请注明原文地址:http://tihaiku.com/zcyy/1501468.html
本试题收录于:
综合A题库综合类分类
综合A
综合类
相关试题推荐
随机试题
[originaltext]Manychildrenfirstlearnthevalueofmoneybyreceivingana
Whatwouldbethenextpictureinthisseries?[img]2021m3s/ct_ve01004003j_eyyjs
某省属高校的青年教师王某在已经领取结婚证书的情况下,又与其任教班级的一名女生发展
下列关于评估行业协会会费管理的说法中,错误的是( )。A.协会不能从事营利性活动
“某教材”勾股定理的内容编排顺序大致为:方格纸呈现两个问题——探索得到规律——一
(2018年真题)根据《金融企业不良资产批量转让管理办法》,下列不属于金融企业批
每一单位药品都符合质量要求是指药品的A.有效性 B.安全性 C.稳定性 D
某企业被认定为国家重点扶持的高新技术企业,2019年度实现技术转让所得700万元
根据我国现行宪法规定,国家保护个体经济、私营经济的合法权利和利益.国家对个体经济
2005-90.治疗外感风寒挟湿之表证,宜选 A.白扁豆B.苍术C.厚朴
最新回复
(
0
)