Birds from Elsewhere: What Do We Call Them?
In recent years, the term "exotic" has come to be used interchangeably with invasive. In the bird world, however, it has long been used as term to describe birds in the pet trade. It therefore is not an appropriate search term to use in trying to locate documents on introduced or non-native birds.
"exotic birds" (1,040,000) "nuisance birds" (13,800) "introduced birds" (12,900) "non-native birds" (11,500) "alien birds" (2,680) "invasive birds" (755) "non-indigenous birds" (233)
In reference to birds, "nuisance" has come to be used to describe any species that is causing economic damage to human interests. It is a term that can be applied to any bird species, regardless of its origins. It can even be applied to species protected in the U.S. by the Migratory Bird Treaty Act.
In marked contrast to such organisms as insects and weeds, the terms "alien" and "invasive" have been applied sparingly (to date) to introduced or non-native birds. "Alien" is applicable in all cases, but "invasive" implies a sub-category of species that are harmful to human interests or ecosystem function.
Although synonymous with introduced and non-native, the term "non-indigenous" has been applied sparingly (to date) in describing such populations of birds.
Thus, the preferred search terms for locating Internet documents relating to bird species outside their native ranges appear to be "introduced" and/or "non-native."