In appearance, the common dolphin is a slender is size with a long or short beak (depending on the species) and also depending on its geographical location. Size does seem to vary between them, but all common dolphins are easily recognised by their hourglass pattern on either side, giving them the local name of hourglass dolphin - not to be confused with the species of Hourglass dolphin. This yellowish-tan patch on either side makes them easy to recognise. Only the Atlantic white-sided dolphin, and sometimes killer whales, share the unique colouration on the thoracic region of their bellies, giving them the local name of "white-bellied porpoise". They have predominantly dark flippers, flukes and fins, with a distinct dorsal fin. Their many small teeth are very sharp and interlocking, allowing them to grip slippery fish easily. Like most dolphins, males are slightly larger than females.
A highly social animal, they are found in tropical waters, and prefers areas where surface temperatures are usually between 10 and 28 degrees. The second most widely distributed of the cetaceans, the common dolphin is found all throughout the world's temperate waters, along coastlines and offshore though mainly in depths of more than 180 metres.
Key Facts of the Common Dolphin: Adult Length: 1.7 metres to 2.6 metres Adult Weight: 70kg to 135kg (155 to 245 ? lbs) Lifespan: The lifespan of the Common dolphin is uncertain. Habitat: These dolphins are found in the temperate and tropical waters of every ocean. Its migrations are directly related to those of the fish upon which it feeds. |
Group size: A pod of Common dolphins can consist of numbers from 10 to 100 and sometimes even up to 3,000! Anywhere from 10 to 500 is more usual though. |
Behaviour:
Common dolphins are very fast swimmers and they often leap clear out of the water showing
off the colourful markings on their flank. They are a very social and
out-going animal. Very active, they enjoy bow-riding and somersaulting, and quite
often when they "porpoise" they cannot be observed due to the froth that they
create. Also very vocal, their whistles and clicks are often heard above the
water's surface as they play. Commonly a friendly animal, this species is not
easily trained.
Reproduction: The female Common dolphin's complete reproductive cycle varies from 12 to 16 months, according to the population. Sexual maturity is sometimes reached at two years of age, although usually between three and four. Mating season also varies but it is usually towards the end of summer. Gestation lasts for 10 to 11 months, and births occur in spring and fall in the northern hemisphere. Diet & Feeding: The diet of this species is relatively varied. It feeds on gregarious and migratory fish, such as anchovies, pilchards, herring and sardines, as well as octopus. Cooperative techniques have been known to be used to capture prey with herds of dolphins driving the schools of fish toward the surface from below. They have been observed catching fish in mid-air! Noteable features: The Common dolphin emerges to breathe a number of times per minute, usually every 20 to 30 seconds. The longest record immersion of this species is five minutes 53 seconds. It can dive to a depth of 280 metres and generally swims at a cruising speed of 5.5 to 9.25 km/hour. When they emerge they jump in all sorts of ways, although sometimes only the melon and back appear. It plays with bow waves and often zigzags. This dolphin is subject to mass stranding. |
Threats: Common
dolphins are the source of many dangers throughout the tropical Pacific region,
Mediterranean, Europe, China, Africa and New Zealand. It suffers greatly
from the fisheries in Japan and South America. Accidental catches are
common making this species the third most frequently caught dolphin in fishing nets and
the like. Many Common dolphins are caught for human consumption in countries
such as Peru, Venezuela, Japan, Spain and various others.
Unfortunately, there have been reports of dolphins being shot in the Mediterranean
for entertainment. The Common dolphin is listed with CITES.
Population: An estimated million is thought to inhabit the southern waters, but the total world population is unknown |
There have been many variations of the Common dolphin that over the years, over 20 species have been proposed.
Common dolphin's flanks are coloured ochre and grey with a distinct dark strip around the eye. Calves display the same pattern but lighter on colour. It is one of the most colourful dolphins.
They have a prominent triangular dorsal fin, pointed flippers and a slender streamlined body.
The Common dolphin can be found along the coast, but it prefers the deep waters.
Common dolphins mainly hunt at night.
Nineteen different
whistle sounds have been recorded by the common dolphin, in comparison to the Bottlenose's
seventeen.
Interesting Common Dolphin Fact:
Two computer-generated Common dolphins were seen bow-riding in the movie Titanic - so accurate was their appearance and bbehaviour that the differences were hard to tell.