Risso’s dolphin

Species profile

Name: the Risso’s dolphin (Grampus griseus) is the only species of dolphin in the genus Grampus. These unusual dolphins are closely related to pilot whales as well as pygmy and false killer whales.

Appearance: Risso’s dolphins have large bodies with narrow tails. They are recognisable by their unusual, bulbous heads. They are often a dark black colour with white scars that cover their bodies, to the extent that older dolphins can appear mostly white. These scars arise from interactions with other dolphins.

Size: they grow to around 3 to 4 metres long and weigh from 300 to 500 kg, making them one of the largest species of dolphin.

Diet: Risso’s dolphins feed almost entirely on squid. They don’t need teeth to eat their prey so they are mostly used in mating conflicts.

Did you know: Risso’s dolphins have complex social lives. They live and travel in groups of 10 to 50 although sometimes form super pods containing up to thousands of individuals. They are known to travel and feed with other species of dolphins and have been seen surfing the waves created by grey whales. In Santa Catalina Island, they live alongside pilot whales and feed on squid around fisherman’s boats.

Location: they are found worldwide in temperate and tropical waters, usually in deeper waters that are close to land.

Where to see Risso’s dolphins

According to reports submitted to WildSide, you can see Risso’s dolphins in the following places:

Place Chance to see User rating No. reports
West Cork
very low
very good

Photo credit: Robin Agarwal under a Creative Commons licence from Flickr

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