Invasive mammal and bird species introduced to the British Isles

The most successful mammal on the planet after humans inhabiting all continents except Antarctica. the dominant rat in Europe and much of North America. Believed to have originated in northern China

Originated in tropical Asia; spread through the Near East in Roman times; reached Europe by the 6th century AD and spread with the Europeans across the world; largely confined to warmer areas.

Native to the eastern and midwestern United States, it's introduction to Britain has nearly displaced the native Red Squirrel.

From mainland Europe. Intruduced in 1842 and now naturalized.

Originally , this rodent was spread through Europe by the Romans , who farmed and ate this mouse as a snack ( hence, the name). It was accidentally introduced to the town of Tring in England through an escapee from Lionel Walter Rothschild's private collection in 1902.

Declining feral population remaining in Bedfordshire

Introduced as game, it is one of the most hunted birds on the planet.

From continental Europe, they are thought to have been intrlduced by the Normans for hunting. Recent evidence suggest earlier populations that disappeared later. These deer are easily tamed and often kept in parks.

From Asia, this deer is one of the few species that do not lose their spots at maturity. A pair that was a gift from King Edward VII in the 1900's escaped into the Sowley Wood and became so prolific they began culling in the 1930's. In areas where they live alongside the native Red Deer there is a serious conservation concern as the two will hybridise.

Introduced into Great Britain from China in the 1870s and were kept in the London Zoo. Feral population resulted from deliberate releases and escapees. Colonization has proceeded slow due to it's preference for a particular habitat: tall reed and grass areas in rich alluvial deltas.

Brought in from North America. Escapees from collections have established themselves in Great Britain and then spread widely into Europe. There, their willingness to interbreed with the endangered native Whiteheaded Duck is a cause of concern.

A pestiferous addition to some parks

from continental Europe

Used as the laboratory mouse it is the most commonly used genetically altered laboratory mammal.

From Asia Escaped from collections and number about 1000 pairs in Great Britain. The species now needs protection, but is not protected in UK since it is not a native species.

From Asia. Feral populations often seen in parks, It is possible they could endanger native populations of birds and may possibly be culled.

Introduced as a game species in Southern England and naturalized.

Originally from Asia, feral populations have established themselves.

Given opportunity, domestic goats from Europe reverted to the wild and have established themselves in some parts of Great Britain.