Seals belong to the group Pinnepedia which means ‘fin footed’. They are highly adapted for life at sea with stores of blubber for insulation, a streamlined body, oily fur and modifications that allow them to hold their breath for long periods under water. They are well designed for swimming and catching and feeding on fish but they must still come ashore to breed and to ‘haul out to rest’, and it would be fair to say that on land they are not always the most elegant of creatures!
The name seal is Old English it may have some connection to ‘sal’, meaning ‘salt’, or ‘sea water’ but it may also be linked to the word ‘selhos’ meaning fish. Females are known as cows and males are bulls, giving birth is known as calving but the young are known as pups. Groups of seals are referred to as herds but their breeding colonies are known as ‘rookeries’. The Gaelic name ‘ron’ may have come from the Norse hraun, meaning ‘a rocky, desolate place and is used more often for the grey seal. The name is thought to be behind the naming of the Islands of North and South Rona, which support the greatest concentrations of breeding Grey Seals anywhere.
There are two native species of seal found in UK waters, the Common Seal and the Grey Seal, both are found around the coast of the estate but the Grey is more abundant in numbers.
Common Seal (Phoca vitulina)
This is the smaller of the two species, although it is similar in colour to the Grey it is easily identified by its ‘V’ shaped nostrils and ‘dog-like face’. The two sexes are similar in size and tend to congregate in much smaller numbers to breed, they tend to breed much earlier than the Greys with pups being born around May/June and the pups can swim at the first high tide after birth.
They are also more of an inshore seal and are also known as ‘harbour seals’ because of this, they are also easier to view than greys and are often seen on rocks ‘posing’ for the cameras!. Despite their name they are actually fewer in number than the Grey seal, their numbers were significantly affected by the Phocine Distemper Virus that struck in the late 1980’s, although the population has since recovered, however the estimated population is thought to be around half that of Grey seals.
Common seals eat a wide variety of foods which tend to vary from one area to another but it tends to include fish, squid and crustaceans.
Grey seal (Halichoerus grypus)
As with the common seal it is the facial profile that makes it easily identifiable, Greys have straight nostrils and a roman nose, their Latin name translates as ‘hooked-nose sea pig’ and it would be fair to say that they are the less attractive of the two species. They are more common than the common seal; it is thought that the British breeding population is around half of the world total for the species, around 90% of the UK’s population is found in Scotland, most of these are in West coast waters.
Grey seals tend to breed on remote, offshore rocks and islands, although they will come ashore to rest on intertidal shores. Unlike the common seal pups, young grey seals are born between September and December and have a white coat for the first few weeks of life – this coat is known as a pelage lanugo, only after they have shed the white coat are they able to enter the sea and swim.
They eat a variety of prey and are known as ‘opportunistic feeders’, which means they will eat whatever is available including squid, salmon, herring and sand eel. In order to get food they can dive to a depth of 200 metres (665 feet), for periods of up to 15 minutes, although if they need to they can go deeper and for longer.
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