Posted 2nd Oct 2014
The magnificent grey seal is a sight to be seen at this time of year as females give birth to gorgeous white, silky fur-covered pups on shores around Britain, making it a true spectacle of the season
Basking in the winter sun, one of the wildlife wonders of the world, the grey seal, returns to British shores at this time of year, ready to haul out and have their pups before Christmas. This incredible spectacle of nature can be seen throughout the UK between September and December, when cows (female seals) give birth to a single pup at a nesting site known as a rookery.
The cute pups are born with thick, creamy white fur which they keep for the first three weeks of their life, before their grey adult coat grows in its place. During these early days the relatively helpless pups will form a strong bond with their mother, feeding on her rich milk which, thanks to its 60% fat content, quickly helps the young seals to pile on the pounds and develop a layer of blubber essential for maintaining their body temperature out at sea. In just a few short weeks the offspring are abandoned by their mothers as they disappear to mate once again, leaving their hungry pups to fend for themselves. In a harsh early lesson the pups have to find their way to sea and hunt for their first taste of solid food alone, and for the next year it is a battle to survive with many sadly not making it to their first birthday.
Despite their tough start in life, seals – a member of the pinniped family – are plentiful in the UK, with an incredible 40 per cent of the world’s grey seal population living in British waters. We are lucky enough to have two resident species of seal here, the grey (pictured above) and the common (pictured left), inhabiting much of the same coastline around England, Wales, Scotland and Northern Ireland. Though difficult to tell apart when wet, the two are easily distinguishable out of water by their size and facial features. The grey seal is much larger than the common, reaching around 2.5 metres in length, whilst the common is around 1.7 metres. The grey seal also has a very distinctive face, attributed in its scientific name ‘Halichoerus grypus’, meaning ‘sea-pig with a hooked nose’, which is exactly what they have, differing from the common seal who has a smaller head and nostrils that form a V-shape. Unlike the grey, common seals have their pups in the summer months between June and August, when their young are born with adult coats and, incredibly, can swim and dive straight from birth. The two species share different breeding behaviours too. Usually solitary animals, the common seal forms far smaller groups than the grey when they haul out to moult and rest, whilst courtship and mating takes place under water. Grey seals on the other hand are land-breeding marine mammals and once a year will come ashore to remote beaches and rocky outcrops in large numbers for the breeding season, during which time the male bull seals gather females into harems and attempt to hold their territory against competitors, which can often lead to the battle of the bulls as they fight dominant males for the right to mate.
Shortly after breeding the moulting season commences – from January to April for grey seals and from August to September for common seals – which provides further opportunity for us to see one of the UK’s most magnificent marine mammals as they haul out once again, though keep a safe distance as they can be very irritable during this time. Seals need to moult their old skin and hair once a year, a high energy task but one that is needed to help protect them from the harsh sea water. The seals gather together in noisy groups for up to six weeks whilst it’s out with the old and in with the new velvety coat that allows them to head back out to sea and resume feeding again.
Britain’s largest land breeding mammal, weighing in up to a massive 300kg, the grey seal is well adapted to life at sea, spending much of their time out in the water hunting for food alone; living on a diet of squid, sand eels and fish. Their two layers of thick fur and layer of blubber helps to keep them warm at sea at all times of year, with webbed flippers helping to propel them through water at a speed of around 5km an hour, whilst their large eyes are well adapted to murky conditions, though it’s their ears that are most important for tracking down prey as their sensitive hearing helps even a blind seal catch their dinner with ease. Though cumbersome when back on land, seals use an incredible amount of strength and energy to haul themselves out and get around by shuffling on their stomachs – but don’t be fooled, they can still move remarkably quick so you should avoid getting too close. These incredible creatures are very curious, known to explore their findings with their whiskers and mouth and enjoy frolicking with floats and lobster pots in the water. When it’s time to rest they are able to sleep in the sea by ‘bottling’, when they stay upright with only their head showing above water, though they can also sleep on shore and often choose to as this is where they rest to digest their food. Seals face some threats out at a sea, including becoming entangled in fishing nets, injury from marine litter, diseases, pollution and feeding from boats, but if they can survive these hurdles seals can live relatively long and happy lives, with both common and grey seals regularly reaching the grand age of 30.
By Natalie Crofts
Read the rest of this feature on p.92 of the Nov/Dec 14 issue...
Images courtesy of The Wildlife Trusts: Eleanor Stone, Margaret Holland, Tom Marshall, Gillian Day