Introduction
The establishment of a species by human agency in an area to which it is not indigenous, also called 'naturalisation'. It may result in the appearance of a feral population which can, ultimately, become truly wild, although many attempts at introduction have failed competely. Examples of species introduced to the British Isles are the Ruddy Duck Oxyura jamaicensis (an escape) and the Little Owl Athene noctua (a deliberate introduction). Many European species have been introduced elsewhere in the world.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver