Many species of parrot have established populations well away from their native ranges (Enkerlin-Hoeflich and Hogan 1997; Fisk and Crabtree 1974; Froke 1981; Garrett 1997; Hall 1988; Hardy 1964, 1973; Johnston and Garrett 1994; Morgan 1993; Neidermeyer and Hickey 1977; Shelgren et al. 1975). In Southern California, at least, several species now occur in what appear to be self-sustaining populations (Garrett 1997).