A Ranger writes

Seals are a common sight around our coastline and come in two distinct species – the grey seal and the common (or harbour) seal. Despite the names, in this part of the world the grey seal is actually the more common of the two species and is much more likely to be seen in our harbours.

Between October and December thousands of grey seals give birth on the Isle of May (the fourth largest UK breeding colony). At birth, the pups weigh around 13 kg and are covered in white fur. For the first three weeks of the pup’s life it is dependent on its mother’s milk, which is high in fat content. During this time the young seal’s weight can quadruple. After weaning, the pup will need these fat reserves to see it through until it takes to the sea and starts to fend for itself.

Occasionally, grey seal pups will be washed up on the shore, particularly after spells of strong northerly winds. If you come across one of these it is important not to approach too close. The pups may look cute, but have very unpleasant teeth and will bite, no matter how helpful you are trying to be. A beached youngster will often simply be worn out and having a rest, under the watchful eye of its mother, who will be waiting offshore. Any approach from humans, especially with dogs, will simply cause unnecessary stress.

Adult grey seals can be big, with males weighing up to 230 kg – by comparison the average bloke in the UK weighs about 87 kg. Underwater, this large size doesn’t hinder them and they can be positively graceful, but on land the term “lumbering” springs to mind. Incidentally, the scientific name for the grey seal is Halichoerus grypus, which means “hooked-nosed sea pig”. Not the most flattering of names, but it does paint a picture.

Common seals are considerably smaller – the largest males might manage a puny 150kg. Females give birth to a single pup in summer and these pups are much more self-reliant than their grey counterparts. They are able to swim after just a few hours, although they will be dependent on their mother’s milk for three or four weeks. Common seals often haul out onto rocks, to rest up or suckle their young. They often assume a characteristic position with the head and tail curved up higher than the body. Morrison’s Haven, near Prestonpans, is a good place to see this behaviour.

The two species can be told apart relatively easily, at least once you’ve got your eye in for the differences. Common seals have rounded heads while greys have long “roman” noses. If it helps, you can think of common seals as looking like reasonably cute dogs and greys as being a bit more horsey. Or something like that. The nostrils are also slightly different, being V-shaped in common seals, but almost parallel in grey seals. However, getting close enough to a seal to get a good look at its nostrils is not recommended – maybe try binoculars for this.