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
Complete the notes below. Write NO MORE THAN TWO WORDS for each answer. Mass Strandings of Whales and Dolphi
Complete the notes below. Write NO MORE THAN TWO WORDS for each answer. Mass Strandings of Whales and Dolphi
admin
2014-09-29
33
问题
Complete the notes below.
Write NO MORE THAN TWO WORDS for each answer.
Mass Strandings of Whales and Dolphins
Mass strandings: situations where groups of whales, dolphins, etc. swim onto the beach and die
Common in areas where the【L31】______can change quickly
Several other theories:
Parasites
e.g. some parasites can affect marine animals’【L32】______, which they depend on for navigation
Toxins
Poisons from【L33】______or______are commonly consumed by whales
e.g. Cape Cod (1988) - whales were killed by saxitoxin
Accidental Strandings
Animals may follow prey ashore, e.g. Thurston (1995)
Unlikely because the majority of animals were not【L34】______when they stranded
Human Activity
【L35】______from military tests are linked to some recent strandings
The Bahamas (2000) stranding was unusual because the whales
were all【L36】______
were not in a【L37】______
Group Behaviour
More strandings in the most【L38】______species of whales
1994 dolphin stranding - only the【L39】______was ill
Further Reading
Marine Mammals Ashore (Connor) - gives information about stranding【L40】______
【L37】
Good afternoon everyone. Well, with some of you about to go out on field work it’s timely that in this afternoon’s session I’ll be sharing some ideas about the reasons why groups of whales and dolphins sometimes swim ashore from the sea right onto the beach and, most often, die in what are known as ’mass standings’.
Unfortunately, this type of event is a frequent occurrence in some of the locations that you’ll be travelling to, where sometimes the tide goes out suddenly, confusing the animals. However, there are many other theories about the causes of mass strandings.
The first is that the behaviour is linked to parasites. It’s often found that stranded animals were infested with large numbers of parasites. For instance, a type of worm is commonly found in the ears of dead whales. Since marine animals rely heavily on their hearing to navigate, this type of infestation has the potential to be very harmful.
Another theory is related to toxins, or poisons. These have also been found to contribute to the death of many marine animals. Many toxins, as I’m sure you’re aware, originate from plants, or animals. The whale ingests these toxins in its normal feeding behaviour but whether these poisons directly or indirectly lead to stranding and death, seems to depend upon the toxin involved.
In 1988, for example, fourteen humpback whales examined after stranding along the beaches of Cape Cod were found to have been poisoned after eating tuna that contained saxitoxin, the same toxin that can be fatal in humans.
Alternatively, it has also been suggested that some animals strand accidentally by following their prey ashore in the confusion of the chase. In 1995 David Thurston monitored pilot whales that beached after following squid ashore. However, this idea does not seem to hold true for the majority of mass strandings because examination of the animals’ stomach contents reveal that most had not been feeding as they stranded.
There are also some new theories which link strandings to humans. A growing concern is that loud noises in the ocean cause strandings. Noises such as those caused by military exercises are of particular concern and have been pinpointed as the cause of some strandings of late.
One of these, a mass stranding of whales in 2000 in the Bahamas coincided closely with experiments using a new submarine detection system. There were several factors that made this stranding stand out as different from previous strandings. This led researchers to look for a new cause. For one, all the stranded animals were healthy. In addition, the animals were spread out along 38 kilometres of coast, whereas it’s more common for the animals to be found in a group when mass strandings occur.
A final theory is related to group behaviour, and suggests that sea mammals cannot distinguish between sick and healthy leaders and will follow sick leaders, even to an inevitable death. This is a particularly interesting theory since the whales that are thought to be most social - the toothed whales - are the group that strand the most frequently.
The theory is also supported by evidence from a dolphin stranding in 1994. Examination of the dead animals revealed that apart from the leader, all the others had been healthy at the time of their death.
Without one consistent theory however it is very hard for us to do anything about this phenomenon except to assist animals where and when we can. Stranding networks have been established around the world to aid in rescuing animals and collecting samples from those that could not be helped. I recommend John Connor’s Marine Mammals Ashore as an excellent starting point if you’re interested in finding out more about these networks, or establishing one yourself.
选项
答案
group
解析
转载请注明原文地址:https://kaotiyun.com/show/ccAO777K
本试题收录于:
雅思听力题库雅思(IELTS)分类
0
雅思听力
雅思(IELTS)
相关试题推荐
EarlylifeinsurersintheUnitedStatesfoundthemselvesfacingtheproblemofobtainingreliableinformation,astheyneededt
ElizabethBishop’sCompletePoems(1927-1979)hascometoseemtomostofitsreaderssoachievedandsufficientasalife’swork
Althoughseveralancientculturespracticedmummification,mummiesfromancientEgyptaregenerallymorewell-preservedthanmum
Mosttelevisionviewersestimatehowfrequentlyaparticulartypeofaccidentorcrimeoccursbyhowextensivelyitisdiscussed
Shouldsportsstarsbegoodrolemodelsforyoungpeople?
Youshouldspendabout20minutesonthistask.Thebargraphgivesinformationaboutthenumberoflibrarybooksborrowedf
Youshouldspendabout20minutesonthistask.Youhavehadabankaccountforafewyears.Recentlyyoureceivedaletterfrom
Youshouldspendabout20minutesonthistask.Thechartbelowshowsthetotalnumberofminutes(inbillions)oftelephonecal
Nowadays,moreandmoreworkcouldbecompletedbythemachineorrobotswithartificialintelligence.Dothepositiveeffectso
READINGPASSAGE2Youshouldspendabout20minutesonQuestions14-26,whicharebasedonReadingPassage2below.
随机试题
下列规范性文件中属于行政法规的是()。
商业银行间,纯粹以信用为基础,没有任何担保的借款业务是()。
在计算机辅助系统中,CAM的含义是
称取重量应准确至所取重量的百分之一,称为取用量不得超过规定量的±10%.,一般描述为取用量
计算机网络按照配置划分为()。
为了减少会计工作量,可以将多笔不同交易或事项合在一起,编制多借多贷的会计分录。()
67,49,55,37,43,25,()
一项研究结果________了在梦中各种感官体验出现的频率,结果显示视觉体验居第一,听觉体验居第二,而触觉、嗅觉和味觉体验的出现频率相当低。视觉和听觉处理与大脑的关系要密切得多,多达三分之二的大脑皮层以某种方式参与视觉。因此,视觉如此频繁地在梦中出现___
通常,MAC地址固化在计算机的(10)中。
选取“人员情况表”的“学历”和“所占比例”两列的内容(合计行内容除外)建立“三维饼图”,标题为“人员情况图”,图例位置靠上,数据标志为显示百分比,将图插入到工作表的A9:D20单元格区域内。
最新回复
(
0
)