Politics in the British Isles converse of unionism, nationalism, is also an important factor for politics in the Isles. Nationalism can take the form of Welsh nationalism, Cornish nationalism, English nationalism, Irish nationalism, Scottish nationalism, Ulster nationalism or independence movements in the Isle of Man or Channel Islands. Identity is intertwined with politics, especially in the case of nationalism and independence movements. Details on identity formation in the British Isles can be found at Britishness, Scottish identity, Irish people. Pan-Celticism is also a movement which is present in several of the countries which have a Celtic heritage. There are no major political parties that are
Introduced species of the British Isles are susceptible. The grey squirrel is a carrier of the squirrel pox virus which kills red squirrels but not grey squirrels. The European crayfish is susceptible to crayfish plague which is spread by the introduced signal crayfish. Unlike some other environmental problems such as pollution, the effect of an introduced species is not a single event. Once a species has been introduced to an island, the problems may persist and escalate as the species spreads further. Coypus "(Myocastor coypus)", large semi-aquatic rodents native to South America, were introduced to the British Isles in 1929 when fur farms were set up