The UK has internationally important seal populations. Seals are Pinnipeds; this name refers to their "winged" or webbed feet. The Order of Pinnipedia has two main groups; Phocids or true seals and Otarids which includes sea lions and walrus. There are two theories as to their evolution; the first is that they all evolved from a common ancestor, the second that true seals evolved from an animal similar to the otter and sea lions from a dog or bear like mammal.
There are obvious differences between Phocids and Otarids. Phocids, the seals found around Britain, don't have ears, only ear apertures and they cannot stand on their hind limbs like sea lions. Seals and sea lions also have different swimming techniques. True seals use their hind webbed feet propelled by strong back muscles while sea lions use their pectoral flippers to "flap" like penguins.
The British Isles are home to two species of phocids; the Common Seal, Phoca vitulina, (also known as the Harbour Seal) and the Grey Seal, Halichoerus grypus, (also known as the Atlantic Seal).
The Common Seal is not as common as its name suggests. Britain is home to about 40% of the European sub-species of Common Seal and 85% of the UK total are in Scottish waters. Common Seals are difficult to count in the wild, partly due to their colouring and distribution amongst rocky, seaweed covered coasts. Between 1996 and 2001 it was estimated that Scotland had approximately 29,700 Common Seals.
The British Grey Seal population is approximately 40% of the world total. Scotland is home to about 90% of the UK population, which amounted to approximately 120,000 in 1996.
Common and Grey Seals are two of the rarest seal species in the world and the UK has international legal and moral responsibilities to protect and conserve them.