No.052 · Mammals · Common
Grey seal
Halichoerus grypus
Britain's biggest land-breeding mammal at sea: a dog-faced, dark-eyed giant that hauls out on quiet beaches and has its white-coated pups in autumn in Wales and in winter in Norfolk.
When to look
July to April, mostly at dawn, day and dusk.
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Time of day
- Dawn
- Day
- Dusk
- Night
- Best time
- Pembrokeshire: all year from the coast path or a boat, pups on quiet beaches August–November (peak September–October). Horsey, Norfolk: pups early November–late January, and moulting seals into the spring.
- Where in the game
- the Pembrokeshire coast (cove, sea, island and sea cliff) and the Norfolk Broads (beach)
- Size
- Females about 1.8 m long; males up to 2.8 m
- Weight
- Females about 155 kg; males up to 300 kg. Pups weigh about 13 kg at birth and about 45 kg by weaning
- Lifespan
- Females up to about 30 years; males rarely beyond 25
- Population
- About 149,500–187,700 in the UK, 34% of the world total (Mammal Society, 2018). About 5,000 around Pembrokeshire (Pembrokeshire Coast National Park). 159 pups born on Skomer in 2024 (Wildlife Trust of South & West Wales; a new counting method, so not directly comparable with earlier years). About 2,500 pups at Horsey and Winterton in winter 2020/21 (Friends of Horsey Seals)
- Status
- Least Concern (Britain and globally; Mammal Society)
Diet
Mostly fish, including sand eels, dragonets, hake, whiting, cod, haddock, pollock and flatfish, plus crustaceans, squid and octopuses
Habitat
Rocky coasts, islands, caves and sandy beaches. Feeds mostly near the seabed in inshore waters and hauls out on quiet shores to rest, moult and breed
Breeding
One pup, born August–January depending on the region. In Pembrokeshire pups arrive from late July to November, mostly in September and October. At Horsey and Winterton in Norfolk they arrive from early November to late January. The pup is nursed for about three weeks, then left by its mother and spends another three weeks fasting while it moults its white coat
Field signs
- A round, dark-eyed face with a long, sloping 'Roman nose' muzzle, unlike the dog-like face of a harbour seal
- Grey, blotchy bodies lying curled like bananas on rocks or a beach, head and tail raised
- A wailing, moaning 'song' carrying from coves and offshore skerries
- White, fluffy pups on quiet beaches from late summer
Did you know?
- A grey seal pup goes from about 13 kg at birth to about 45 kg in just three weeks, fed on milk that is 50–60% fat, ten times richer than a Jersey cow's (Friends of Horsey Seals).
- Ramsey Island, near St Davids, has 500–700 pups born each year, the largest grey seal pupping site in southern Britain. On Skomer the record was 265 pups in 2021.
- Its Latin name, Halichoerus grypus, means 'hook-nosed sea pig' (Mammal Society).
Moments worth waiting for
- White-coat pup
On a quiet beach a white-coated pup lies motionless while its mother watches the surf, ready to nurse. - Pups on the Horsey beach
A fluffy white pup squirms on the sand below the dunes as the cows shuffle and call around it.
Photo tip
Use a 300–500 mm lens from the coast path or a boat and never step closer for a better angle. Get your eye level near the animal's (lie on the cliff edge or shoot from a low boat) so the picture is not all back and rocks. Pups are bright white against dark rock: underexpose by a stop to keep the fur detail. Overcast light is kinder than noon sun.
Be a good naturalist
Seals are easily disturbed, and a scared mother can leave her pup. From a boat keep at least 20 m away, preferably 50 m, and never land on a pupping beach or come between a mother and her pup (Pembrokeshire Coast National Park). Watch from the cliff with binoculars where you can. At Horsey stay in the marked viewing areas behind the rope and fence, and keep dogs away: disturbed seals head for the sea, and a pup separated from its mother is likely to die (Friends of Horsey Seals).
The law
Protected by the Conservation of Seals Act 1970 and the Conservation of Habitats and Species Regulations 2017 (Mammal Society). Haul-outs and pupping beaches must be left undisturbed