Two species of True seal exist around the UK seaboard, the Common seal, Phoca vitulina, and the Grey seal, Halichoerus grypus. Occasional vagrants visit our shores including Walrus, Ringed seal, Harp seal, Hooded seal and Bearded seal, but so rarely as to be discounted.
Atlantic Grey and Common Seals are resident in our plying area.
The most common seal is the Grey or Atlantic, which may be any colour from black to white through various shades, including piebald, and the less common is the Common - if you get the drift! Statistics are like the pup in the pic., a bit wooly. It is likely that there were around 200,000 Grey seals and 30,000 Commons off the UK shores in 2004.
Distinguishing features for the Grey are:- its size - generally twice the weight of its Common counterpart - Male bulls have been known to grow up to half a ton or 500kgs in weight. Grey seal nostrils appear as nearly parallel slits while those of the common seal form a “V” shape. The long Roman nose of the male Grey is unlikely to be confused with the short “pug” nose of the Common though the females of both species are more difficult to distinguish. Grey seals are distributed widely round our coasts (ex English Channel).
During breeding time - September - November on the West Coast of Scotland, they accumulate in certain areas like The Treshnish Isles to pup and mate (conception takes place within 3 weeks of the birth). The pup is a helpless white/yellow furry creature scrabbling around the high tide mark for its first few days of life. Mother comes ashore to feed with a high concentration milk which makes the pup large and fat at the rate of up to 2kg per day! After about three weeks of intensive growth the pup is left to its own devices and as it loses its fur and developes a sleek new coat for seagoing, another remarkable warm-blooded mammal has adapted perfectly to the harshness of life in our temperate seas.
By mid-October, several hundred seals will be ashore and have given birth around the Treshnish Isles, creating the impression of a moving “live” beach in some areas.
Common seals are usually brown to grey in colour and are frequently better camouflaged in their chosen environment - usually closer inshore in more sheltered waters than their larger relatives.Pupping takes place during June/July. Pups take to the water within a few hours of birth and to this end, are born with a sleek coat and large hind flippers to keep them in close proximity to their mother for the first four weeks of life. Lactation periods vary - about 28 days for Commons and 16 - 21 days for Grey seals.