The smallest of the Dolphins commonly seen around the Hebrides, this species reaches lengths of 1.6-2.0 metres. They have a dark grey back, cream underneath and a distinctive pale hourglass pattern on the side, this tends to be yellow at the front and grey at the back. They also have a distinctive beak or rostrum and a curved dorsal fin.
There are two species of Common Dolphin worldwide; the short-beaked and the long-beaked, the species seen around the Hebrides are the short-beaked. This species is more numerous worldwide and can be found in most warm temperate and tropical waters, the long-beaked also inhabit warm temperate and tropical waters, however they are restricted to more coastal waters around South America, Japan, West Africa and California south to Mexico.
Common Dolphins are summer visitors to the Hebrides and are seen between May and September.
It is a very acrobatic species and the first sign of them can be splashing which at times can be seen from a couple of miles away. When close to the boat they will often approach the boat and bow-ride. The groups seen in local waters usually number 10-50 individuals, however it is possible to see aggregations of 100's or even 1000's of individuals, especially further offshore.
Common Dolphins feed on Squid and a range of fish species, including mackerel and herring and can often be seen feeding in association with gannets. They will often work as a group to round up schooling fish, to make it easier to catch them. As with all toothed cetaceans they use their teeth to grasp prey, but in general swallow them whole.
Despite being one of the planets most numerous cetacean species with an estimated population of several hundred thousand, the worldwide Common Dolphin population is decreasing. This is due to accidental capture in fishing gear, pollution and lack of food due to overfishing.