History of the British Isles History of the British Isles The British Isles have witnessed intermittent periods of competition and cooperation between the people that occupy the various parts of Great Britain, the Isle of Man, Ireland, the Bailiwick of Guernsey, the Bailiwick of Jersey and the smaller adjacent islands. Today, the British Isles contain two sovereign states: the Republic of Ireland and the United Kingdom. There are also three Crown dependencies: Guernsey, Jersey and the Isle of Man. The United Kingdom comprises England, Northern Ireland, Scotland, and Wales, each country having its own history, with all but Northern Ireland having been independent states at
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