438 



Non-ualiw Specif) — Our Ltviiii^ Rfsources 



Table. Population trends from the 

 Breeding Bird Survey. 1466-92. 

 Dashes under "Population trend" 

 indicate insufficient data; dashes 

 under "Significance" indicate no 

 significant chaniies. 



many city parks, but is less commonly found in 

 the wild where it must forage for itself. Many 

 European and some Asiatic ducks, and even a 

 few exotic geese, escape from private collec- 

 tions, especially during stomis. Because the 

 number of these individuals is small, their pop- 

 ulations have not been monitored. 



"Probability values are given for those species with a significant continuing decline for the entire survey period 

 "Less than 1% change per year on average. 



The mute swan of Eurasia is the notable 

 exception. Introduced on Long Island and the 

 lower Hudson Valley of New York in the late 

 I800"s (Bump 1941), this swan is now locally 

 common around Long Island Sound, in the 

 Maryland portion of Chesapeake Bay, and in 

 the Great Lakes region. Small populations 

 tlirive in other localities. Recent population 

 increases (Table) and the resulting destruction 

 of submerged aquatic vegetation needed by 

 native waterfowl are causing concern. 



Upland Game Birds 



Most exotic birds imported for release are 

 nonmigratoiy gallinaceous species: pheasants 

 and francolins from Asia and partridges from 

 Europe. Most were released to provide more 

 hunting opportunities. Some states, such as 

 Oregon, still have active introduction pro- 

 grams. 



The only two Old World species to have 

 become established widely enough to be mon- 



itored by the BBS are the ring-necked pheasant 

 and the gray (Hungarian) partridge (Table). 

 The first successful release of ring-necked 

 pheasants was the release of 199 pairs in the 

 Willamette Valley of Oregon in 1881 (Bump 

 and Robbins 1966). Ring-necked pheasants 

 have become an important game species in the 

 northern states, but have had detrimental 

 effects on remnant populations of the greater 

 prairie chicken (Tympanuchiis ciipido: Vance 

 and Westemeier 1979). Gray partridges have 

 been in America since 1908-09, when nearly 

 40.000 birds, mostly wild-trapped in Hungary, 

 were released in the United States and Canada 

 (Bump and Robbins 1966). 



Doves 



The domestic pigeon or rock dove was first 

 introduced from Europe by French settlers in 

 the early 16()()"s (Schorger 1952). Now they are 

 one of the most noticeable birds in American 

 cities and farming communities. Countless 

 thousands are still reared annually by pigeon 

 fanciers who use them for homing and racing 

 competitions, and each year the feral population 

 is supplemented by captive-reared individuals 

 that fail to return home. Rock dove populations 

 were ignored by scientists and bird watchers 

 before the Breeding Bird Survey began in 1966 

 and were not reported on Christmas Bird 

 Counts until 1974. The population appears to 

 have stabilized following a sharp increase in the 

 1960'sand 1970's (Table). 



Introductions of several other dove species 

 have been successful locally, especially in the 

 mild climates of Florida, California, and 

 Hawaii, but these species are not sufficiently 

 widespread to be monitored by existing surveys. 

 The spotted or lace-necked dove {Streptopelia 

 chinensis) of eastern Asia was well established 

 in the Hawaiian Islands before 1900. and local 

 populations have been established in southern 

 California since 1917 (Willet 1933). The 

 species now also occurs on St. Croix in the 

 Virgin Islands (Raffaele 1989). 



Likewise, the small baned or zebra dove 

 (Geopelia striata) was brought to the Hawaiian 

 Islands in 1922. and by 1936-37 it was common 

 on all the major islands except Hawaii. Ten 

 years later the Hawaiian population was esti- 

 mated at 237.000 birds (Schwartz and Schwartz 

 1949). 



The ringed turtle-dove or Barbary dove 

 {Streptopelia risoria) has been domesticated so 

 long that its origin is uncertain. Small popula- 

 tions are established in southern California, 

 eastern Texas. Florida, and Puerto Rico. 

 Occasional individuals occur each year in more 

 northern states. A close relative, the Eurasian 

 collared-dove (S. decaocto), has bred in south- 

 em Florida since the late 1970's (Smith 1987) 



