Cetaceans - Whales, Dolphins and Porpoises : page 1
Porpoises and Dolphins
All cetaceans are mammals, so although otherwise fully adapted to aquatic life and unable move around on land, they still need to breathe air. Unfortunately, on rare occasions they do come ashore and although they won't immediately die, like a fish out of water, if you come across any cetacean stranded on the beach it is in dire trouble : click here for advice on what to do. |
There are ninety species of whales, dolphins and porpoises worldwide, of which 29 have been recorded in British waters although 11 of those are listed by the WDCS as "rare." This still leaves eighteen possible species of which two, the Harbour Porpoise and the Bottlenose Dolphin live close inshore and the rest usually in deeper waters. |
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Harbour porpoise |
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Harbour porpoises are the smallest of the British cetaceans, at around 2 metres when fully mature, and although Bottlenosed dolphins vary widely in size around the world, the biggest ones are found in British waters, at up to 4 metres in length! Common dolphins are only a little larger than porpoises but have a distinctive "hourglass" marking in yellow or tan, grey and white and the names of the Atlantic White-sided, Striped and White -beaked,dolphins all tell what they look like. Bottlenosed dophins are the dolphin most people think of by the term "dolphin" and have no distinctive markings, being dark grey above and lighter grey below. The remaining dolphin likely to be found in British waters is Risso's dolphin, which is distinctive in not having a "beak" and also, the skin of older animals is usually criss-crossed with white scars and scratches. When born they are grey all over, and then become chocolate-brown and eventually pale grey with a pale underside. |
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 Atlantic white-sided dolphin |
 Striped dolphin |
 White-beaked dolphin |
 Risso's Dolphin |
 Bottlenosed dolphin |
The Orca, commonly known as the Killer Whale, is biologically a dolphin but because of its great size (up to 10 metres in length) is frequently classed along with the true whales.
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The Pilot whale is also a large dolphin : it has a bulbous forehead (melon), single blowhole, and is black or dark grey in colour with very long black flippers and a backward-leaning fin, set forward on its body. It grows up to 8 metres in length.
 Long-finned Pilot Whale |
