Identification at a glance
This species grows to 3.9 m long.
They have:
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- No beak and a broad head
- A tall, often raked, hooked dorsal fin
- Colouration is variable. Dark to pale
- Scarring visible on the sides of many adults and occasionally juveniles
- Long flippers
Range
Risso’s dolphin is widely distributed throughout the world’s temperate and tropical waters, ranging from Newfoundland, the Gulf of Alaska and the North Sea, south towards South America, Southern Africa, Australia and New Zealand.
Risso’s dolphin is also found in a number of partially enclosed waters, including the Red Sea, Gulf of Mexico and Mediterranean Sea.
They appear to migrate northwards during winter, with some individuals sighted as far north as the Gulf of Alaska and the Shetland Islands.
Habitat
Behaviour
Diet-squid, octopus, crustaceans and cuttlefish.
Risso’s dolphins are very sociable and inquisitive, often seen breaching, spy-hopping and slapping their heads and tails on the water. They are mainly late afternoon and nocturnal hunters, and in the daytime can be seen slowly swimming, resting or socialising.
They can be known to exhibit rough behaviour, with their extensive scarring primarily caused by aggressive interations with other Risso’s dolphins, or the beaks and tentacles of their prey, mainly squid.
Fun fact:
Risso’s dolphins are also the only species of cetacean to possess a distinct vertical crease on its forehead.
Threats
Threat Level
IUCN Listing: Least Concern