List of endemic species of the British Isles

The British Isles have few endemic species due to past frequent glaciations and because of the proximity to Continental Europe and former land bridges which enabled species to re-colonise the islands from the continent following glaciations. Most endemic taxa to the British Isles are considered to be subspecies of a more widely spread species, with mutations or adaptations slightly changing the species in the islands or in certain localities.

Source: Wikipedia — List of endemic species of the British Isles (CC BY-SA 4.0)