Common Dolphins

The Common dolphin is the name given to two seperate species which make up the genus Delphinus. The two recognised are the Short-beaked Common dolphin, Delphinus delphis, and the Long-beaked Common dolphin, Delphinus capensis. Despite its name, the Common dolphin is not the species we usually picture when we think of dolphins. This distinction belongs to the Bottlenose dolphins. The Short-beaked Common dolphin has a wider range than the Long-beaked, found throughout warm temperature and tropical oceans, including the Indian Ocean. It is the most numerous dolphin species in the warm-temperate areas of the Atlantic and Pacific Oceans. The Long-nosed Common dolphin has a similar, but more restricted range, staying in warmer and tropical waters in the Pacific, Atlantic and Indian Oceans.

Despite the historic classification of these two distinct species as one, these widely distributed dolphins exhibit a wide range of sizes, shapes and colours. Both Common dolphin species are medium sized, with adults ranging between 1.9 and 2.5 m (6-8 ft) long, weighing in anywhere between 80 and 235 kg (176-518 lb), with males generally longer and heavier than females. Common dolphins have an unusual, and thus recognisable color pattern. The back of the dolphin is invariably dark, with a white underbelly, and a hourglass pattern colored light grey, yellow, or gold in front, and grey in back. Short-beaked Common dolphins generally prefer deeper and cooler water, but when it comes to feeding, both species dive to at least 200 m (660 ft) deep to feed on many species of schooling fish, krill and cephalopods (e.g. squid).

Common dolphins are regularly found in large social groups with 100-500 individuals, but are well documented in so-called “mega-pods”. These mega-pods consist of thousands of individuals, sometimes over 10,000 dolphins congregate in one pod. These large pods are then interestingly thought to consist of many sub-groups of 20-30 individuals, separated by age and/or sex. This means that Common dolphins are one of the most exciting species to watch due to their distinctive appearance, highly developed social structures, and the sheer number of individuals that can be seen in one location.