Seals are marine mammals in the order Pinnipedia. They are thought to be descendants of animals such as weasels and bears, which became more aquatic. The word Pinniped is used to refer to ‘true seals’ that is ones that lack externally visible ears and also Sealions and Fur Seals. The Walrus is also considered a Pinniped, but it’s in a family of its own, Odobenidae. They are in places, some of the most visible marine mammals in Britain. There are only two species that are regularly present in Scotland, with others that occasionally stray from the Arctic and have occurred as vagrants.
They are warm blooded and breath air, though they are capable of diving for extended periods in search of fish, squid, whelks, crabs and mussels. Unlike whales and dolphins, they are unable to live permanently at sea and have to come ashore to breed and digest their food. Whilst they can be seen anywhere along the coast, there are particular places where they haul out in large numbers, usually along sandy beaches, rocky shorelines and estuaries. Such places are important for breeding and resting and thus highly vulnerable to disturbance from people and dogs. Therefore, it’s important to never disturb seals at their colonies, as they have to expend a lot of energy escaping to the water.
The two species of seal that we have in Scotland and the wider UK are relatively easy to identify, though females of both species can sometimes be confused.
Common Seal (Phoca Vitulina) - Also known as the Harbour Seal in North America and in fact the most widespread pinniped in the world. Nowadays, it’s the less common of the two seal species regularly seen in Britain with an estimate of 55,000 individuals. They are smaller, growing to a length of about 1.85 metres, with shorter flippers, a rounder face and they have variable coat colours. Though they’ll always have dense brown spots, the pattern of which is unique to every individual. Some are silvery white, tan or grey. When seen hauling out, Common Seals have a tendency to do so with plenty of personal space. Unlike Grey Seals, they don’t like to bunch together. If another seal comes too close to their haul out place, they tend to growl to ward them off. Sometimes they can be seen lying in a ‘banana’ posture, that is, with their tails raised and their bodies arched.
They have their pups in June and July. When inside the womb the pups shed their white coats and come out with more or less their colours that they will have in adulthood. Each female gives birth to only one pup, which they raise alone. Pups are able to swim and dive within hours of being born, which is an adaptation to the fact that some of their haul out sites can be periodically submerged by the tide, especially if they are living in an estuary with sandbanks. The mothers nurse them with some of the richest milk in the animal kingdom, richer than cow’s milk, so rich that they can be weaned within four to six weeks. The pups in particular can sometimes be prey for Porbeagle Sharks and Orcas, the latter come from Iceland in order to prey on them.
Atlantic Grey Seal (Halichoerus Grypus) - The larger of the two species, growing up to two metres and the most common, with an estimated 120,000 individuals. Male Grey Seals have large noses, often referred to as a ‘Roman nose’, that is, one that is broad like Romans were supposed to have been. They have parallel nostrils that don’t join together at the bottom, by contrast to the V-shaped nostrils of Common Seals. Female Grey Seals are smaller overall, with a less broad nose than the male and have grey backs, with yellowish bellies that are covered in grey blotches.
They can haul out in large colonies with minimal personal space, as in, they have absolutely no problem bunching together.
By contrast to Common Seals, they have their pups in November and December, possibly to reduce competition between the two species and perhaps because there are fewer predators around. The pups themselves have white fluffy coats, presumably to give them better insulation during the autumn and winter and can swim almost immediately after birth. The bulls or ‘Beach Masters’ as they’re sometimes referred to, stake their territories in the colony and try to create as big a harem of females as possible, whilst chasing other males away that might compete with them. Sometimes all that’s needed to do this is to chase them off, but at other times physical fights break out and during such times they aim bites at each other’s necks and noses, though these physical spars are usually brief and rarely last longer than a few minutes.
If you would like a chance to see our seal species you can book one of our guides at: http://bit.ly/sw_DG
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