A predominantly deep-water species that can sometimes be seen closer to shore.

In brief

• A relatively large, robust dolphin reaching 3.7-4 m.
• Distinctive large, blunt head.
• Deep-water species that can occasionally be spotted closer to shore.
• Current population status is unknown and this species is data deficient.

Species 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.

Life cycle: Can live 35-40 years. Females mature around 8-10 years old. Gestation lasts 13-14 months, with the calf heavily dependent on their mothers for an extended period of time.

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

How to see this species: 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.

Current status: Data deficient. Population trends for Northern Irish waters unknown, but habitat and range deemed to be in favourable condition. Possibly under-recorded. Thought to be more common in NI waters than the common dolphin, Delphinus delphis.

Why is this species a priority in Northern Ireland?

• Criterion 1: Internationally listed species.

Threats:

• Vulnerable to hunting on a global scale.
• Environmental change could affect their range and range and availability of prey species.
• Vulnerable to chemical and noise pollution.
• At risk of entanglement in fishing nets.

Action: Records of new sites for this species, with details of habitat and population are always valuable. Observations with a photograph can be recorded using iNaturalist, find the MBDP-NI iNaturalist project here.

Alternatively, records can be sent to CEDaR, National Museums Northern Ireland, 153 Bangor Road, Cultra, Holywood, County Down, BT18 0EU. Tel 028 9039 5257, e-mail cedar.records@nationalmuseumsni.org, or via the online portal.

Objectives:

• Assess current population utilising Northern Irish waters.
• Maintain current range and density of population.

Conservation:

• Protected under The Conservation (Natural Habitats, etc.) (Amendment) Regulations (Northern Ireland) 2007.
• Listed under The Conservation of Habitats and Species Regulations 2010 - Part 2 and Part 3.
• Protected under Bern Convention (Convention on the Conservation of European Wildlife and Natural Habitats) Appendix III.
• Listed in Appendix II of the Convention on the Conservation of Migratory Species (The Bonn Convention).
• Covered by the terms of the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS).
• Listed in Annex A of EU Council Regulation 338/97 and therefore treated by the EU as if they are on CITES, Appendix I.
• Listed in Annex IV (Animal and Plant Species of Community Interest in Need of Strict Protection) of the EC Habitats Directiv.e
• Listed in Part II and III of The Conservation (Natural Habitats, etc.) Regulations (Northern Ireland) 1995.

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

iNaturalist: Grampus griseus at iNaturalist World Species Observations database.

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