Irish scientists monitoring dolphins living in a river estuary in the southwest of the country believe they may have developed a unique dialect to communicate with each other. The Shannon Dolphin and Wildlife Foundation 1 has been studying a group of up to 120 bottle-nose dolphins in the River Shannon2 using vocalisations collected on a computer in a cow shed3 near the River Shannon.
As part of a research project, student Ronan Hickey digitised and analysed a total of 1,882 whistles from the Irish dolphins and those4 from the Welsh dolphins on a computer and separated them into six fundamental whistle types and 32 different categories5. Of the categories, he found most6 were used by both sets of dolphins7 but eight were only heard from the Irish dolphins.
We are building up a catalogue of the different whistle types they use and trying to associate them with behaviour like foraging, resting, socialising and the communications of groups with calves, project leader Simon Berrow said. Essentially we are building up what is like a dictionary of words they use or sounds they make.
Berrow, a marine biologist, said the dolphins clicks are used to find their way around and locate prey. The whistles are communications. They do a whole range of other sound like barks, groans and a kind of gunshot, he said. The gunshot is an intense pulse of sound. Sperm whales use it to stun their prey.
When I first heard it I was surprised as I thought sperm whales were the only species who used it. We can speculate the dolphins are using it for the same reason as the sperm whales. Borrow said.
References in local legend8 indicate there have been dolphins in the Shannon estuary for generations and they may even have been resident there as far back as the 6th century9.
They are regularly seen by passengers on the Shannon ferry and an estimated 25,000 tourists every year take special sightseeing tours on local boats to visit them.
练习：
1. The difference in eating habits between the bottle-nose dolphins and the sperm whales interested the SDWF scientists.
A Right B Wrong C Not mentioned
2. Ronan Hickey analysed almost 2,000 different dialects of the bottle-nose dolphins.
A Right B Wrong C Not mentioned
3. Of the 32 categories, eight were produced only by the Irish dolphins.
A Right B Wrong C Not mentioned
4. Whistles could also be used to communicate between adult dolphins and baby dolphins.
A Right B Wrong C Not mentioned
5. Sperm whales can produce stronger ultrasonic waves to kill their prey than dolphins.
A Right B Wrong C Not mentioned
6. As early as the 6th century, Irish fishermen started raising dolphins in the Shannon estuary.
A Right B Wrong C Not mentioned
7. Irish dolphins attract tourists and over 25,000 people come to see them every year.
A Right B Wrong C Not mentioned
答案与题解：
1. C 本题所说的意思是宽吻海豚与巨头鲸送食习惯上大相径庭，这一点令科学家很感兴趣。题句表达的内容短文中找不到，故答案为 C。
2. B 题句的意思是： Ronan Hickey分析了爱尔兰海豚发出的近 2000种不同的方言。这句话与短文中叙述的意思不符。第三段第一句说： Ronan Hicke分析了爱尔兰海豚和威尔士海豚发出的近 2000种不同的啸声 。所以，本题选项 B是答案。
3. A 题句表达的意思与第三段第二句所述的内容相符。 32种啸声中有 8种是爱尔兰海豚独有的。所以答案是 A。
4. A 短文第四段第一句说科学家正在设法将啸声与海豚的行为特性联系起来，其中也包括成年海豚与小海豚之间的联络这一行为。题句的意思与原句的意思相符，所以答案是 A。
5. C 本题所说的态思是鲸鱼能发出比海豚更强烈的超声波去杀死猎物。题句表达的内容短文中找不到，故答案为 C。
6. B 短文第七段说的是，早在公元 6世纪海豚就在香农河河口繁衍生息，而没有说早在公元 6世纪渔民开始在香农河河口养殖海豚。题句的意思与文章的意思不符，所以答案是 B。
7. A题句表达的意思与最后一段的意思相符。原文说大约每年有 25000名游客专程到此乘坐当地的小船观看海豚。所以答案是 A。