Red squirrel vs grey squirrel: 6 key differences in size, appearance, habitat, diet and more

Britain’s red squirrels have lived there since the last Ice Age, but grey squirrels arrived from North America in the late 19th century. Greys now dominate with 2.7 million, while fewer than 287,000 reds remain. Greys carry a deadly virus and eat food before it matures, causing red squirrel numbers to fall.