While the whiskery face of a grey seal popping out of our coastal waters will always remain a delight to spot, in no way could this fleeting view be labelled a ‘spectacle’. For the real seal deal you should instead head to a select number of beaches around our coastline, which at this time of year play host to an astonishing annual fiesta of synchronised pupping, before the boorish bulls then gate-crash the party with just one thing on their minds: mating again.


If you do go seal watching, it's vitally important not to disturb them. Follow the guidelines listed below to ensure that both adults and pups remain undisturbed and able to continue with their normal behaviours.

One of just two pinnipeds breeding along our coastline, the other being the common or harbour seal (below), it is ironically the grey seal that is more abundant.

Common seal hauled out on a rocky shoreline
Common seal hauled out on a rocky shoreline in the Scottish Highlands. © Richard Stelmach/Getty

Greys were originally thought to have bred across the entire northern Atlantic until the end of the last Ice Age, when the population was effectively split between the east and west sides of the ‘pond’. And with Britain holding the majority of the eastern stock of seals, our convoluted coasts host about 45% of the entire world population during the breeding season.

Discounting whales, the grey seal is our largest British mammal. It's thought that the heaviest males could weigh close to 300kg, or nearly twice that of the more slimline females.

When are grey seal pups born?

The mass production of grey seal pups is very much an autumnal phenomenon. Having spent the previous nine months fattening up out at sea, the pupping season kicks off when the first pregnant females begin hauling themselves up the beach. They return to the beach where they were born to give birth.

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A small pup with white fur rests with its eyes closed on a sandy beach next to some seaweed. Behind it a grey speckled adult (its mother) looks at it.
A baby grey seal with its mother on the beach. © Nisangha/Getty

Favoured birthing spots tend to be both smooth and sandy, and anywhere from above the high-tide line to in amongst sand dunes several hundred metres from the water’s edge.

Although twins were recently confirmed on the Farne Islands in 2016, a single pup is very much the norm, with the birth of the 15kg pup often occurring rapidly and with little indication of any discomfort during labour. The majority of births also occur within a short window, as the species adopts a safety-in-numbers strategy originally designed to swamp predators.

A grey seal pup with white fur lays on its back amongst the marram grass, facing the camera with its mouth open and its paw on its neck.
A grey seal pup lying on its back at Donna Nook Nature Reserve in Lincolnshire, England, UK. © Jacky Parker Photography/Getty

Once born, the mother will then constantly sniff and touch the pup to quickly learn its smell and help avoid becoming separated from it.

With the beach births fo rapid and discreet, often the first sign that a pup has arrived is when an unseemly squabble of gulls breaks out on the beach. These supreme scavengers will quickly descend to fight for the membrane that enclosed the pup, and then again for the placenta when it is expelled shortly after.

An adult herring gull walking on the beach at the Horsey grey seal colony in Norfolk, England, UK. © Ian Dyball/Getty
An adult herring gull walking on the beach at the Horsey grey seal colony in Norfolk, England, UK. © Ian Dyball/Getty

The pup’s distinctive creamy white fur coat is thought to originate from when the species bred in icy landscapes. But certainly since the last Ice Age, a lack of natural predators in modern Britain has reduced the evolutionary necessity to remain camouflaged. The white fur is shed when a pup is between two and three weeks old.

Sometimes melanistic grey seal pups can be born (below), where they have a black fur coat instead of white, at a frequency of roughly one in every 400 pups.

A young grey seal pup with black velvety fur amongst grass.
A melanistic grey seal pup at Donna Nook Nature Reserve, England, UK. © Stefan Istrate/Getty

Do grey seal pups drink milk?

Almost immediately after birth, the pups must latch on to their mother’s nipple as ‘operation weight gain’ commences. Resembling mayonnaise, the milk consists of 60% fat, so the pups can easily double their weight in the first week.

Pups will suckle their mother five to six times a day for three weeks, gaining about 2kg of weight every day. However, the lactation period lasts no more than three weeks and it’s crucial the youngsters quadruple their birth weight before the milk bar runs dry.

Once weaned, the pups are abandoned, and with high mortalities occurring both on the beach and during their first few months at sea, sadly only about two-thirds will survive to reach their first birthday.

However, once this difficult first year is negotiated, their prospects become brighter, and hopefully they’ll participate in the mating game three or four autumns further down the line.

When do grey seals mate?

Male grey seals are usually darker in colour than the females, and are often scarred as a result of battles. The males will usually begin competing with each other for access to the females when the first pups are born. Size matters, as the biggest bulls or ‘beachmasters’ fight for exclusive access to between two and ten females.

Their large energy stores mean they can go for a long time without eating and stay ashore for longer, increasing potential mating opportunities.

Two male grey seals in the surf of beach. One is very dark and lifting its head into the hair, the other is covered in sand and has its mouth open, looking sideways.
Two male grey seals hauled out during the breeding season at Horsey Gap in Norfolk, England, UK. © Sarah Weston/Alamy

Relations between adjacent and dominant males are mostly amicable, but when a large, harem-less interloper attempts a takeover, the ensuing battle can be spectacular, with savage bites. And with the females rapidly coming in to oestrous (or heat) by the end of the lactation period, it really is a case of ‘to the victor, the spoils’.

Best places to see grey seal pups in the UK

When going to view seals, it is very important not to disturb them – particularly when there are pups. Some key rules to follow:

  • Don't get closer to a seal than 20m
  • Never get between a seal and her pup, or between a seal and the sea
  • Noise should be kept to a minimum
  • Dogs need to be kept on short leads and under control

Disturbance to animals including seals, cetaceans and seabirds causes a change in animal behaviour, raising stress levels, and triggering the flight, fight or freeze response, and can mean that eggs or young animals are abandoned, animals are separated from the group, previous energy is waster, and injury or death can occur.

A report from Cornwall Wildlife Trust found that the number of reported disturbance events nearly tripled between 2014 and 2020, with coastal users and walkers causing the highest number of seal disturbances, followed by tripper boats and paddle sports.

A seal pup with white fur rests on the sandy and stony beach looking at the camera.
A young grey seal pup on the beach in Norfolk, England, UK. © Bjorn Stefanson/Getty

Monach Islands, Outer Hebrides, Scotland

Situated off the west coast of North Uist in the Outer Hebrides, these uninhabited islands must be accessed by boat, but 10,000 grey seals come ashore here in autumn.

Orkney Islands, Scotland

The islands host many grey seal colonies around the dramatic coastline. One of the best viewing spots for ‘selkies’, as the locals call them, is from the cliff top at Burwick on South Ronaldsay.

Farne Islands, Northumberland, England

This area off the Northumberland coast is famous for its summer seabird colonies, but is also home to thousands of grey seals each autumn. Seal counts are undertaken every year.

Horsey and Winterton, Norfolk, England

Head to these sites along the Norfolk coast to spot a relatively accessible seal colony. Volunteer wardens will help you see the seals from the sand dunes.

Donna Nook National Nature Reserve, Lincolnshire, England

This Lincolnshire spot has a large grey seal colony that produces about 1,500 pups a year. The Ministry of Defence uses the area just offshore as a bombing target range.


Main image: A female grey seal face to face with her pup in the sand dunes in Lincolnshire, England, UK. © Jacky Parker Photography/Getty


Mike DilgerNaturalist, presenter and writer