Explore Animals.im
seals.animals.im
The big facts page

46 seal facts, all checked

Every fact on this site, each linked to its source. Figures that can change carry the date we checked them (5 Nov 2026). Where sources disagree we keep every figure: see when sources disagree.

Jump to: Seals in the UK | Telling them apart | Bodies and diving | Food | Life cycle | Where and when | Populations and status | Red List | Law | Watching and threats

Seals in the UK

  1. 1 Two seal species live and breed around the UK all year: the grey seal and the harbour seal (also called the common seal). Natural History Museum: Seals in the UK
  2. 2 Both belong to the family Phocidae — the true, or earless, seals. Natural History Museum: Seals in the UK
  3. 3 The grey seal is Britain’s largest resident seal. Adults can grow to more than 2.5 metres long and weigh up to about 300 kg. Natural History Museum: Seals in the UK
  4. 4 Harbour seals are smaller: roughly up to about two metres long and around 70–150 kg. Natural History Museum: Seals in the UK
  5. 5 Harbour seals are also called common seals, but in the UK they are the less common of the two species. Natural History Museum: Seals in the UK
  6. 6 Britain’s shores hold a large share of Europe’s grey seals: the Natural History Museum puts the UK population at about 120,000, roughly 40% of the world total and about 95% of the European population. Natural History Museum: Seals in the UK

Telling them apart

  1. 7 In profile, grey seals have a flatter, more ‘Roman’ nose; harbour seals have a dished, dog-like face with a clearer forehead. SMRU: Identifying seals leaflet
  2. 8 Grey seals have nearly parallel nostrils; harbour seals have V-shaped nostrils that almost meet at the bottom. Natural History Museum: Seals in the UK
  3. 9 The grey seal’s scientific name, Halichoerus grypus, means ‘hook-nosed sea pig’. Natural History Museum: Seals in the UK
  4. 10 Harbour seals are usually more evenly spotted; grey seals often show larger, more irregular blotches and a clearer contrast between a pale belly and a darker back. SMRU: Identifying seals leaflet
  5. 11 Grey seals often show a double chin; harbour seals do not. SMRU: Identifying seals leaflet

Bodies and diving

  1. 12 A thick layer of blubber under the skin keeps seals warm and helps streamline the body. MarLIN: Common or harbour seal
  2. 13 Grey seals can detect the wake of a fish tens of metres ahead using their sensitive whiskers. Mammal Society: Grey seal
  3. 14 Grey seals usually stay underwater for about four to eight minutes; the longest recorded dive in Mammal Society notes is about 30 minutes. Mammal Society: Grey seal
  4. 15 MarLIN records harbour seals diving to 450 m and staying submerged for up to 30 minutes. MarLIN: Common or harbour seal
  5. 16 The Mammal Society notes harbour seals diving for up to about 10 minutes and reaching depths of at least 50 metres on feeding trips. Mammal Society: Harbour seal
  6. 17 The Natural History Museum notes grey seals have been recorded deeper than 400 metres, though they often hunt in shallower water. Natural History Museum: Seals in the UK
  7. 18 Grey seals do not feed during the pupping and moulting seasons. Mammal Society: Grey seal
  8. 19 Grey seals need to eat roughly 4–6% of their body weight in food each day when feeding normally, to maintain their blubber. Mammal Society: Grey seal

Food

  1. 20 Grey seals mainly eat fish (including sand eels, cod, flatfish and others) and also take squid, octopus and crustaceans. Natural History Museum: Seals in the UK
  2. 21 Harbour seals take a varied mix of fish such as herring, sand eels and cod, plus squid, octopus and sometimes crustaceans. Natural History Museum: Seals in the UK

Life cycle

  1. 22 Grey seals around the UK mostly pup between September and December (timing varies by coast: earlier in the west, later in the east). Natural History Museum: Seals in the UK
  2. 23 Grey seal pups are born with fluffy white coats and stay ashore for about two to three weeks before entering the water. Natural History Museum: Seals in the UK
  3. 24 By about a month old it is normal for a grey seal pup to be left alone on the beach while the mother feeds at sea — it is not usually abandoned. Natural History Museum: Seals in the UK
  4. 25 Harbour seals usually pup in June and July. Natural History Museum: Seals in the UK
  5. 26 Harbour seal pups are born ready to swim and can enter the water within a few hours of birth. Natural History Museum: Seals in the UK
  6. 27 Seal pups drink rich milk — about 2.5 litres a day — and put on insulating blubber quickly. Natural History Museum: Seals in the UK
  7. 28 Harbour seal mothers suckle for about three to four weeks; pups roughly double their birth weight in that time. Mammal Society: Harbour seal
  8. 29 Grey seal females can live up to about 30 years; males seldom survive beyond about 25. Mammal Society: Grey seal
  9. 30 Harbour seal females can reach about 30 years; males are unlikely to live beyond about 20. Mammal Society: Harbour seal

Where and when

  1. 31 Grey seals live around the North Atlantic: the Baltic, Iceland, northern Europe including the UK and Ireland, and the east coasts of Canada and the USA. Natural History Museum: Seals in the UK
  2. 32 Both species haul out on coasts to rest, digest, socialise, moult and — for grey seals especially — to pup on remote beaches and islands. Mammal Society: Grey seal
  3. 33 Harbour seals often pup on intertidal sandbanks or rocks that are only exposed for part of the tide. SMRU: Identifying seals leaflet
  4. 34 Grey seals moult roughly from December to March. SMRU: Identifying seals leaflet
  5. 35 Harbour seals moult roughly from July to September (often counted from the air in August). SMRU: Identifying seals leaflet

Populations and status

  1. 36 UK grey seal pup production in 2022/23 was estimated at about 79,122 — the highest total on the SCOS record — with over 70% of those pups in Scotland. SCOS scientific advice on UK seal populations (2025 report) · checked 5 Nov 2026
  2. 37 Based on surveys between about 2016 and 2023, SCOS estimates the total UK harbour seal population at about 36,956 (95% confidence interval about 30,200–49,300). SCOS scientific advice on UK seal populations (2025 report) · checked 5 Nov 2026
  3. 38 SCOS reports that harbour seal numbers are declining and/or depleted in most UK Seal Monitoring Units with notable numbers. SCOS scientific advice on UK seal populations (2025 report) · checked 5 Nov 2026
  4. 39 The UK Marine Strategy 2026 update says Good Environmental Status has been met for grey seals, but harbour seals have not yet achieved it in the Greater North Sea and are declining in places such as north-east Scotland and south-east England. UK Marine Strategy part one update 2026 · checked 5 Nov 2026
  5. 40 NatureScot’s 2021–2025 August surveys, scaled by haul-out probability, estimate about 27,750 harbour seals and about 63,800 grey seals in Scotland. NatureScot Research Report 1421: aerial surveys of seals in Scotland 2021–2025 · checked 5 Nov 2026

Red List

  1. 41 The IUCN Red List assesses the grey seal (Halichoerus grypus) as Least Concern globally, with an increasing population trend. IUCN Red List: Grey seal (Halichoerus grypus) · checked 5 Nov 2026
  2. 42 The European IUCN assessment for the harbour seal (Phoca vitulina) is Least Concern, though some local populations are of concern. IUCN Red List: Harbour seal European assessment · checked 5 Nov 2026
  3. 43 NAMMCO notes the harbour seal as Least Concern on the global IUCN Red List, with a very large worldwide population, while stressing that local stocks can be stable, increasing or declining. NAMMCO: Harbour seal · checked 5 Nov 2026

Law

  1. 44 In the UK, seals are protected under the Conservation of Seals Act 1970 and, in Scotland, the Marine (Scotland) Act 2010; NERC’s Special Committee on Seals (SCOS) advises government on their management. SCOS scientific advice on UK seal populations (2025 report)

Watching and threats

  1. 45 A lone seal pup on a beach is often waiting for its mother. Keep your distance, keep dogs away, and call a local rescue if the pup looks injured or is in clear danger — do not put it back in the sea yourself. Natural History Museum: Seals in the UK
  2. 46 SCOS reports hundreds of seals bycaught in UK fisheries each year (around 400–600 in recent estimates), with many of those young grey seals in south-west waters. SCOS scientific advice on UK seal populations (2025 report) · checked 5 Nov 2026