There are 33 species of seal world-wide, two of which live around Britain.
Scotland is an important breeding area for grey seals.
The grey seal population is estimated to be increasing by seven per cent a year.
Neither grey seals nor common seals are an endangered species.
Grey seals are larger than common seals, and have a distinctive profile.
Unlike whales and dolphins, seals give birth on land.
Seals are insulated from the cold by a thick layer of blubber.
Grey seals mate on land, but common seals usually mate in water.
Seals have sensitive whiskers that help them to detect prey in murky waters.
As soon as a pup is born, its mother forms a bond with it by smelling and calling to it.
Grey seals have been known to live for 46 years.
Some seal species have been hunted almost to extinction in some parts of the world.
In 1988 phocine distemper virus killed about 33 per cent of all common seals in the North Sea.
Oil spills are thought to cause breathing problems in seals, as well as damage to ears, nose and throat.
Seals are wild animals if approached too closely they will bite.