List of endemic species of the British Isles

Part of a series on the
Wildlife of Great Britain
Fauna England Cornwall Isles of Scilly Scotland Highlands Outer Hebrides Wales Endemic Extinct
Invertebrates Insects Ants Aquatic heteropteran bugs Bees Beetles Butterflies Conopid flies Damselflies and dragonflies Hoverflies Mayflies Moths Orthoptera and allied insects Shield bugs Soldierflies and allies Wasps Molluscs Non-marine molluscs Crustaceans Crabs Woodlice
Vertebrates Amphibians Fish Mammals Reptiles Birds British avifauna Wales Non-natives North American landbirds Feral parakeets Bee-eaters Cranes
Flora Ferns and allies Conifers Dicotyledons (Superrosids Asteraceae Rosaceae) Monocotyledons British National Vegetation Classification
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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.^[1] Most endemic species to the British Isles are considered to be subspecies of a larger species, with mutations or adaptations slightly changing the species in the islands or in certain localities.

British conservationists often describe this as a "wiped clean effect" with repeated glaciations forcing many species out of the modern area of the islands to more southern latitudes in Europe and perhaps even driving some species extinct.^[1]

Some species which were present in Britain before past glaciations, often during periods with a warmer climate than now failed to return after the Last Glacial Maximum. Amongst these are Rhododendron ponticum and rabbits, now considered invasive and non-native.

A species is only deemed native if it reached the British Isles without human intervention (either intentional or unintentional). That means that to be native the species must have reached Britain before the land bridge joining Britain to the continent was submerged. Alternatively species can also be native when they have flown or swum to Britain as is the case with many bird species which arrived after the submersion of the land bridge, a recent example is the collared dove which arrived in the 1950s, this also applies for plants which spread seed in the wind.

A few endemic species are Arctic-Alpine species, survivors of Arctic species of plants and animals which either adapted to the warming climate or became isolated in suitable areas of mountains or lakes which still retained a suitable micro-climate. A common misconception is that the entirety of the British Isles was under glaciers and was uninhabitable both for humans, plants and animals. Whilst unsuitable for most species, a number of Arctic species survived in the areas not under glaciers in southern areas of England, Wales and south west Ireland and were either driven to extinction in the British Isles or to micro-climatic refuges as the climate warmed and the Arctic conditions retreated north.

Most endemic species or subspecies however date to more recent, post-glacial times, many having spread via land bridges or along the Atlantic seaboard of Europe.