There are two species of squirrel in the UK; red squirrels and grey squirrels. Populations are currently estimated at approximately 140,000 red squirrels and 2.5 million grey squirrels.
Red squirrels have lived in the UK for around 10,000 years. At that time, the UK was connected to Europe by a low-lying marshy region, later flooded by the north sea. Squirrels could freely move from the Continent to England without having to obtain an EU Export Health Certificate
Grey squirrels were introduced to the UK from North America by the Victorians in the 1800s, the first record of them escaping and establishing a wild population is 1876.