About The Seals

Amazing Things You Might Not Know About Grey Seals

• Grey seals are thought to be able to dive to depths of 300m and stay underwater for up to 20 minutes.
• Grey seal milk contains up to 50-60 % fat, ten times more than a Jersey cow’s milk.  This helps the pups gain weight rapidly and develop a layer of blubber. Pups go from their birthweight of around 13kg to 45 kg in just three weeks.
• Grey seals can end up in some odd places on their travels. In 2014 a seal was rescued from a farmer’s field more than 20 miles from the sea and a seal treated and tagged by the RSPCA at East Winch and subsequently turned up in Dunkirk.
• Grey seals and other pinnipeds (seals, sea lions and walruses) use highly sensitive whiskers known as mystacial vibrissae to detect fish-generated water movements when hunting in murky water with poor visibility or dark conditions. 
• Adult grey seals typically have a wedge-shaped head and characteristically long nose with wide nostrils which run parallel and vertically down the nose. The species scientific name for grey seal (Halichoerus grypus) translating to ‘hooked-nosed pig of sea’.
• Pups are born with a white coat known as a “lanugo”. They moult this after they are weaned, around 3 weeks after they are born. The process of growing a shorter adult waterproof coat takes another 3 weeks or so.
• Approximately 40% of the world’s grey seals breed in the UK. In the winter of 2020/21 season 2,500 pups were born at Horsey and Winterton.
• Grey seals typically return to breed and moult to one particular location and female grey seals often return to have their pups at the colony where they were born. 
• Female grey seals only suckle pups for 17 to 23 days and then their job is done. She leaves never to return. Pups then stay behind on the beach alone for around another three weeks to moult their white coats and grow a grey waterproof one. They fast during this time living off their fat. 
• When they are ready the pups go into the sea and teach themselves to fish.
• Male Seals are called bulls, female Seals are cows and baby seals pups.
• Bulls live for up to 25 years and reach sexual maturity at 6 years. Cows live for 35 years and start to breed at between 3 to 5 years.
• Cow seals can weight up to 250 kg and bulls up to 350 kg.
• Seals do not spend all of their time in the sea. They need to come ashore, or haul out to moult, rest and digest their food. They are warm blooded air breathing mammals.
• Seals are highly intelligent and show that when escaping a predator or hunting for a meal.
• Seals can sleep on or even underwater. They can float vertically in the sea, with just their heads poking out of the water to breathe. This is known as bottling. Others can slow their heartbeat down to conserve oxygen and roll around on the seabed enjoying forty winks for up to two hours.
• Our seals are a protected species. It is estimated there is 640,000 tonnes of fishing litter and other rubbish currently polluting the world’s oceans. Sadly, our rescue team are catching more and more seals with fishing lines, ropes, nets or plastic objects stuck around their necks. The injuries they sustain can be horrific.