Irish Dolphins may have a unique dialect
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 (SDWF)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 sounds 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," Berrow said.
References8 in local legend 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.
Irish adj. 爱尔兰的 socialise v. 社交，交往
bottle-nose dolphin 宽吻海豚 sperm whale 巨头鲸
click n. 咔哒声，喀嚓声
estuary n. 河口，江口
vocalisation n. 发声
shed n. 小屋，棚
digitalise v. 使数字化
whistle n. 啸声
forage v. 搜寻(食物) prey n. 被捕食的动物
gunshot n. 射击声
groan n. 呻吟，叹息
pulse n. 脉冲
stun v. 击昏
1. The Shannon Dolphin and Wildlife Foundation (SDWF): 香农海豚与野生生物基金会。
2. the Shannon River：香农河[ 位于爱尔兰共和国的中西部]
3. cow shed: 牛棚
4. those 指代前半句的 whistles。
5. Ronan Hickey…separated them into six fundamental whistle types and 32 different categories： Ronan Hickey 将啸声划分为6大类32种
6. most = most categories
7. both sets of dolphins 是指 the Irish dolphins 和 the Welsh dolphins。
8. References in local legend:：当地传说中的有关说法
9. they may even have been resident there as far back as the 6th century：海豚可能早在公元 6 世纪就在香农河河口繁衍生息，resident 是形容词，意思是 “居住的”。