Half of the world's population of grey seals are found on and around British coasts, and numbers here have doubled since 1960.

Statistics
Body length: Male: 210cm, Female: 180cm, Weight: Males: 230kg, Females: 155kg.

Physical description
Male grey seals are much larger than the females, and have broad shoulders, an elongated snout and a heavy muzzle. The females have a thinner snout and a less rounded profile. They vary in colour from dark brown to grey or black with blotches, and females tend to be paler than the males.

Distribution
Grey seals inhabit the North Atlantic Ocean.

Habitat
Grey seals come ashore to breed on exposed rocky shores.

Diet
Grey seals mainly feed on fish, but will also rarely take cephalopods (squid and octopus) and crustaceans.

Behaviour
The females arrive at the breeding sites first, to give birth. When the males come ashore they compete for space nearest to the females. The oldest males get the best positions, but there is little fighting.

Reproduction
The gestation period is 11.5 months, including a three month delay in the implantation of the fertilised egg. The pup weighs about 15 kg at birth and is born with a white coat. Pups gain about two kg of weight a day due to the high fat content of their mother's milk (60 per cent fat). After three weeks of suckling the pup, the female mates again and then leaves the breeding area (rookery).

Conservation status
Grey seals are protected by the Conservation of Seals Act, but individuals causing damage to fishing nests can legally be killed. The northeast Atlantic subpopulation is considered to be Endangered by the 2000 IUCN Red List.