- Lifespan
- 25–40 years in the wild
- Size & Weight
- 1.6–2.0 m in length; males 150–310 kg, females 100–180 kg
- Habitat
- Coastal rocky islands, skerries, and haul-out sites in cold temperate and subarctic waters around the British Isles.
- UK Distribution
- Found around Scotland (especially Orkney, Shetland, and the Hebrides), Wales, Cornwall, and Northern Ireland. Resident year-round with seasonal movements; populations have expanded southward in recent decades.
- Diet
- Primarily fish species including cod, pollack, whiting, and flatfish; also takes crustaceans and cephalopods. Diet varies by region and season.
- Prey
- Fish (cod, pollack, whiting, flatfish); crustaceans; cephalopods
- Predators
- Adults have few natural predators in UK waters; pups may be vulnerable to large sharks and occasionally killer whales; historical hunting by humans was significant.
- Mating Season
- September to November
- Breeding
- Single pup born per female after gestation of ~11.5 months; pups are weaned after 3–4 weeks. Breeding occurs in large terrestrial haul-outs.
- Behaviour
- Highly social, forming large haul-outs on rocky islands. Males are territorial during breeding season and engage in aggressive displays. Grey seals are excellent divers, capable of reaching depths over 400 m and remaining submerged for up to 30 minutes while foraging.