Description: Males grow to around 3.7 m, females to around 4 m, and can weigh up to 500 kg. Distinctive stocky or bulky build when compared to other dolphins of a comparable size. They do not have any sort of beak but instead have a large, blunt head. When young they are a black, grey or brown colour but as they age they begin to develop a lot of white colouration, mostly as a result of scarring from altercations with squid and tooth rakes from other dolphins. Mature adults may appear almost completely white. Usually found in groups of 10-30 animals, but some times alone or in small groups or occasionally larger pods. Their dorsal fin is a tall, heavily curved sickle shape and located about halfway down their back.

Habitat: This species is usually prefers deep water but can occasionally be seen closer to shore. Most likely to be seen on a calm day from a headland.

Distribution: Population trends for Northern Irish waters unknown. Possibly under-recorded. Thought to be more common in NI waters than the common dolphin, Delphinus delphis.

Similar Species: Unlikely to be confused with any other species.

Key Identification Features:

• Distinctive stocky or bulky build.
• Large blunt head.
• Tall, heavily curved sickle-shaped.

Distribution Map from NBN: Grampus griseus at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Grampus griseus at iNaturalist World Species Observations database.

GBIF data for Grampus griseus

WoRMS: Grampus griseus at World Register of Marine Species. Accepted name: Grampus griseus (G. Cuvier, 1812). AphiaID: 137098.

Classification: Biota; Animalia; Chordata; Vertebrata; Gnathostomata; Tetrapoda; Mammalia; Theria; Cetartiodactyla; Cetancodonta; Cetacea; Odontoceti; Delphinidae; Grampus