First it was cows who moo with a Somerset drawl. Then it was birds with regional accents. Now scientists say that dolphins living off the coast of Wales have developed a Welsh dialect.

The dolphins’ distinctive inflection was discovered by researchers trying to build a dictionary of nearly 2,000 whistles.

After studying the 240 dolphins in Cardigan Bay, they found that the mammals had their own unique series of Welsh dialect whistles, different from other dolphins around Britain.

Simon Berrow, project leader, said: “We’re trying to associate whistle types with different forms of behaviour – like foraging, resting, socialising and communicating with their young.

“One was distinctive and exclusive to the dolphins of Cardigan Bay.

“We’re really building up a dictionary of a whole range of sounds. There are whistles, clicks, barks, groans and a gunshot sound which they might use to stun their prey.”

The study was made by marine scientist Ronan Hickey, of the University of Wales, Bangor, and experts from the Shannon Dolphin Foundation in Ireland. They analysed 1,882 whistles from 120 Irish Sea dolphins and found the Welsh dolphins had their own accent.

Cardigan Bay is one of two important locations off the British coast for bottlenose dolphins. The other area is Moray Firth. There are two major local groups of dolphins, one off New Quay and the other off Llangrannog.

Although these dolphins are seen locally throughout the year, they have also been observed off the Irish coast. Timings of these observations suggest that they can swim across to Ireland in just a few hours. Steve Hartley, the manager of the Cardigan Marine Wildlife Centre, said: “It makes sense that different groups of dolphins separated by large distances have different accents. It’s nice to know they have their own Welsh accent.

The finding was backed by academics who suggested similar changes of inflection are to be found in birds. Researchers at the RSPB claimed that the Scottish crossbill is Britain’s only endemic bird on the basis of its unique accent. Ornothologists had discovered that great tits in Buckingham Palace are developing a distinctly urban patois.

A study of Christmas broadcasts since 1952 suggests the royal vowel sounds have also undergone a subtle evolution.

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