Seals in Scotland
Where are they?
Seals spend most of the time at sea, and might swim thousands of miles during their lives in search of food. They come ashore for three reasons: to breed, to moult, and to rest between fishing expeditions.
There are several areas in particular in Scotland where seals congregate each year to breed and to moult.
The most important of these include the Orkney and, to a lesser degree, the Shetland Islands, the Hebrides, including North Rona, and the Monach Isles, which is the second largest breeding colony of grey seals in the world. Seals are also born at some sites on the Scottish mainland each year, for example at the sea caves around Helmsdale and at Loch Eriboll.
Outside the breeding and moulting seasons, seals haul out on beaches, sandbanks and rocks, either alone or in small groups, to rest between fishing expeditions.
Both species can be seen all around Scotland on many of the offshore islands, along much of the west mainland coast and also on the east coast, in areas such as the Moray Firth, the Firth of Tay and the Isle of May. Because seals range widely in their search for food, single seals of either species might be spotted anywhere along the Scottish coastline.
Seals use a variety of habitats as pupping sites on land. Some use flat sandy beaches, like Shillay in the Outer Hebrides, while others use flat platforms of rock, like the coast near Muckle Greenholm in Orkney. Still others use grassy areas above the sea, like some parts of North Rona, or offshore sandbanks.
When can they be seen?
Grey and common seals do not breed or moult at the same time of year. Female and male grey seals begin to arrive at the main breeding beaches towards the middle of September, and pups are born from the end of September until mid December. Mating occurs about three weeks after the female has given birth. Females moult between mid January to late February, while males moult between mid February and early April.
The annual cycle of common seals is earlier than that of grey seals. They begin to arrive at the breeding grounds in June, and most births take place at the end of June and the beginning of July. Mating takes place when a cow has finished (or almost finished) suckling her calf. Common seals moult in August and September.
How many Scottish seals are there?
British seal numbers are estimated regularly using a variety of different techniques. Aerial photographs can be taken, and the number of seals counted from the photograph – easier than trying to count seals moving around on a beach. Sometimes seals are counted using binoculars from a boat or from the ground.
The most recently developed method is to use helicopters fitted with a ‘thermal imaging’ camera. This camera is able to detect the warmth of a seal’s body, and can estimate how many seals are within a given area.
These surveys have shown that in 1994 there were some 99,400 grey seals around the Scottish coast and islands, and that the population is increasing at a rate of about 7 per cent a year. About 36 per cent of the world population of grey seals breeds around Britain, and the Scottish breeding grounds are therefore especially important.
There are far fewer common seals than grey seals around Scotland, and British common seals comprise only about 5 per cent of the total world-wide population. There are a minimum of 26,400 common seals around Scotland during the breeding season although this number may be much higher.
Occasional seal visitors to Scotland
Seals travel hundreds of miles in search of prey, and occasionally a seal might wander far away from its usual feeding areas. These include ringed and harp seals, and, more rarely, hooded and bearded seals.
Ringed seals are smaller than grey and common seals, and are characterised by a very distinctive pattern of light-coloured rings on a grey pelt. Their bellies are silvery-grey.
Harp seal adults have very distinctive pelts unlike grey or common seals. They are grey-white with dark faces and a ‘harp’-shaped band across the back. Females are slightly lighter, although there is considerable variation in the colour of both sexes.
Bearded seals are larger than grey and common seals and are greyish-brown. Their most distinctive feature is a wealth of white shiny whiskers that grow from the sides of their distinctly flattened snouts.
Hooded seals are grey, with black irregular patches which are larger towards the tail. Adult males have an amazing inflatable hood on their heads, which they blow up when excited or alarmed. In some males, the hood may be twice the size of a football. These seals can also inflate part of their nasal tissues into a large red balloon.