Old- Liviiis; KcsDiiivcs — Non-native Species 



4.n 



and has been found as tar north as Louisiana 

 and Georgia. Its rapid spread across Europe in 

 the past tew decades suggests its potential tor 

 rapid expansion in America. 



Parrots 



Many species of parrots imported for the 

 cagehird trade have escaped, especially at ports 

 of entry. The budgerigar (Melopsittucus uudiiki- 

 tits) from Australia and the canary-winged para- 

 keet (Bwtogcris versicoliirus) from South 

 America have established populations in south- 

 em Florida and Puerto Rico, while the parakeet 

 has become established in Los Angeles County. 

 California. Of greater concern to orchardists has 

 been the survival and reproduction in more 

 northern states of monk parakeets (Myiopsitia 

 monachiis) from temperate South America (Bull 

 1975). Control measures have eliminated most 

 populations of this exotic species in the United 

 States. 



Songbirds 



Berger ( 1981 ) includes accounts of 37 exot- 

 ic songbird species that maintain breeding pop- 

 ulations in Hawaii, and Raffaele (1989) lists 19 

 that are breeding or probably breeding in Puerto 

 Rico. Fewer nest on the U.S. mainland. The two 

 most notorious species that dominate the envi- 

 ronment and have negative effects on native 

 species are the house sparrow and European 

 starling, both of which compete with native 

 birds for nesting cavities. 



One hundred house sparrows from England 

 established the first breeding population in New 

 York City in 1851-52. Additional introductions 

 helped the population spread westward to the 

 Mississippi River by 1870. and by 1910, this 

 species was established across the continent 

 (Robbins 1973). Their numbers continued to 

 expand until the automobile replaced the horse 

 and the supply of waste grain was markedly 

 reduced. Their decrease since the mid-1960's is 

 well documented by the BBS (Table). 



Sixty European starlings released in New 

 York City in April 1890 (Cruickshank 1942) 

 were the ancestors of the millions that now 

 occupy the American countryside. Although 

 these birds consume enomious quantities of 

 noxious insects and weed seeds, they are seri- 

 ous competitors with native species for nesting 

 cavities and food. Fortunately, their populations 

 seem to have peaked and are now declining 

 (Table). 



The house tlnch (Carpodacus mexicamis), 

 native to the western states, is an adaptable 

 species that has rapidly colonized the East since 

 the illegal release of the species on Long Island, 



New York, in the early 1940"s. The birds now 

 breed in every eastern state. 



Migratory Immigrants 



In addition to birds intentionally relea.sed in 

 North America, two migratory species, the cat- 

 tle egret (already discussed) from Africa and the 

 parasitic shiny cowbird {Molothrus bonari- 

 eii.sis) from South America, have invaded via 

 the West Indies in recent decades. Shiny cow- 

 birds, which lay their eggs in the nests of other 

 songbirds, may be as real a threat to the repro- 

 ductive success of native North American 

 species as they have been to the yellow-shoul- 

 dered blackbird {Agelaiiis .\au!hi}nuis) in Pueilo 

 Rico (Wiley 1985). Shuiy cowbirds have been 

 found as far north as Maine and as far west as 

 Texas and Oklahoma. 



Future Concerns 



The North American avifauna has developed 

 over millions of years, changing as climatic 

 conditions altered habitats. New species 

 evolved; others became extinct. Today, human 

 influences are speeding extinction rates without 

 any comparable increase in evolution of new 

 species. Introducing aggressive exotic species 

 often results in unforeseen problems, including 

 extinction of native species. 



References 



American Omitliologists' Union. 1983. Ctiecl<-list of Nortli 

 American birds. 6tli ed. Allen Press, Lawrence, KS. 877 

 pp. 



Berger, A.J. 1981. Hawaiian birdlife. 2nd ed. University of 

 Hawaii Press. Honolulu. 260 pp. 



Breeze, PL. 1959. Information on the cattle egret, a bird 

 new to Hawaii. 'Elepaio 20;3.3-.^4. 



Bull. J. 1975. Introduction to the United States of the monk 

 parakeet — a species with pest potential. International 

 Council for Bird Preservation Bull. 12:98. 



Bump, G. 1941. The introduction and transplantation of 

 game birds and mammals into the state of New York. 

 Transactions of the North American Wildlife Conference 

 5:409-420. 



Bump. G., and C.S. Robbins. 1966. The newcomers. Pages 

 343-353 in A. Stefferud, ed. Birds in our lives. U.S. Fish 

 and Wildlife Service, Washington, DC. 



Cruickshank, A.D. 1942. Birds around New York City. 

 American Museum of Natural History Handbook Series 

 13. New York. 489 pp. 



MacArthur, R.H.. and E.G. Wilson. 1967. The theory of 

 island biogeography. Princeton University Press, NJ. 203 

 pp. 



Raffaele, HA. 1989. A guide to the birds of Puerto Rico and 

 the Virgin Islands. Princeton University Press, NJ. 254 

 pp. 



Robbins, C.S. 1973. Introduction, spread, and present abun- 

 dance of the house sparrow in North America. Pages 3-9 

 in S.C. Kendeigh, ed. A symposium on the house sparrow 

 (Passer domesticus) and European tree spaiTow (Passer 

 niiinianus) in North America. Ornithological Monograph 



