What is a common dolphin? Common dolphins (Delphinus delphis) are easy to identify because of the beautiful, attractively coloured hourglass patterns on their sides and other distinctive markings. These boisterous mammals seem to enjoy bow riding, breaching and somersaulting clean through the air.
What does it look like? Common dolphins have an hourglass pattern of light grey and tan or yellow on their sides and a dark stripe from flipper to lower jaw, with a long well-defined black beak. Calves display the same patterns but are lighter in colour. They have a prominent triangular dorsal fin, pointed flippers and a slender, streamlined body. Average length varies according to the location, but is about two metres.
Vision courtesy of MIRG Australia (www.mirg.org.au)/Blue Office Productions
Where do they live? Common dolphins are widely distributed throughout deeper offshore waters in tropical, subtropical and temperate areas. A good place to see them is in the Archipelago of the Recherche around Esperance, if you go out on a boat trip to Woody Island Nature Reserve.
What they eat and how: Common dolphins often work together in groups to catch a variety of prey, although their favourite foods are squid and smaller schooling fish like sardines, anchovies and pilchards. The movements of common dolphins are probably related to feeding opportunities.
Behaviour: Common dolphins are highly vocal and produce a range of clicks and whistles used for both communication and navigation. They live in large herds, ranging from dozens to more than 1000. The males tend to hang out together in their own groups, and so do females and their calves.
Breeding and caring for young: Females calves every two years or so. In tropical waters calving probably occurs all year round. In more southern areas, calves tend to be born in late spring and early summer. The gestation period lasts for about a year, with the single young suckling for another year or more.
Conservation status: Common dolphins are one of the world's most abundant dolphin species so they are not threatened. They are, however, fished in Japan, South America and elsewhere, which means that some populations of animals in these countries are not as large as they would be without such fishing pressure.
Protecting the common dolphin: Strandings of common dolphins are not common. The best thing you can do to protect this animal is to make sure you dispose of rubbish properly when you are in a boat or at the beach.
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