Canada goose. Photo: Kristin S. Karlsen

Alien mammals and birds have reached Norway in various ways:

• Pheasants and Canada geese were introduced solely for their utilitarian value, i.e. to serve as game. 
• Mink, polecats and rabbits have escaped from captivity. Mink now occur throughout the country, except some islands off the coast. 
• The raccoon dog and muskrat have escaped from captivity (fur farms) in Eastern Europe, and now form permanent populations as far west as Finland. Several muskrat populations in Finnmark are growing rapidly. In 2006 the raccoon dog established a small population in the Skibotndalen in Troms County. 
• Muskoxen used to be a part of the Norwegian fauna 30 000 - 100 000 years ago, but became extinct during the last interglacial stage. The population on the Dovre mountain was introduced in the period 1947-1953. 

Mammals that have been introduced into Norway (incl. Svalbard), or have immigrated from neighbouring countries to which they have been introduced

Birds that have been introduced and established breeding populations in Norway (incl. Svalbard)