Pheasants Threaten Greater Prairie-Chickens in Illinois

Found in remarks concerning establishment of the 407-acre Jasper County Prairie Chicken Sanctuary Nature Preserve in February 1972 (excerpt):

Fewer than 100 prairie chickens remain in Illinois. One problem that threatens the existence of the prairie chicken [Tympanuchus cupido] is the introduced ring-necked pheasant [Phasianus colchicus], native to Asia. The pheasant parasitizes the prairie chicken nest with its own eggs, which then hatch earlier than the chicken’s. The confused prairie chicken hen leaves her nest with the young pheasants, unaware that her parasitized nest will not produce any young prairie chickens to repopulate the sanctuary.

This is one of two prairie chicken sanctuaries in Illinois; the other is located in Marion County.

Following the establishment of these preserves in 1972, prairie-chicken numbers soared—to 400 birds in Jasper County by the early 1970s, and to 230 birds in Marion County by 1982. But by spring 1994, the Jasper County population had declined to six Illinois cocks plus two translocated Minnesota cocks. In Marion County, the number of cocks ranged from 9-18 from 1992-1996.

Once again, one of the “factors documented to have decimated prairie numbers” was “intense interactions with pheasants” (excerpt):

Illinois Department of Natural Resources (IDNR) sanctuary managers have successfully controlled nest predators and pheasants in recent years. So far, genetic management via translocation of prairie chickens from large populations in Minnesota, Kansas, and Nebraska also appears successful. From only 6 Illinois cocks in spring 1994, numbers increased to 70 cocks by spring 1996 on at least four well-established booming grounds in Jasper County.

Sources:

Illinois Department of Natural Resources. No date. Jasper County Prairie Chicken Sanctuary Nature Preserve. Illinois Nature Preserves Commission.
http://dnr.state.il.us/INPC/Directory/Sitefiles/Area8/JASJA.htm

Illinois Department of Natural Resources. No date. Marion County Prairie Chicken Sanctuary Nature Preserve. Illinois Nature Preserves Commission.
http://dnr.state.il.us/INPC/Directory/Sitefiles/Area8/JASJA.htm

Westemeier, Ron. 1997 (January-February). Grassland for prairie chickens: how much is enough? Illinois Natural History Survey Reports.
http://www.inhs.uiuc.edu/inhsreports/jan-feb97/chicks.html

Introduced Birds of Illinois

Ruffed Grouse (Bonasa umbellus), Greater Prairie-Chicken (Tympanuchus cupido), Wild Turkey (Meleagris gallopavo), and Peregrine Falcon (Falco peregrinus) are all native to Illinois, but native populations have been supplemented to a greater or lesser extent by introductions or reintroductions, as described here (excerpts):

• Ruffed Grouse in NW Illinois may represent a remnant native population or wild dispersals from Wisconsin or Iowa. A very small population in Pope County may be the result of late 1950’s or early 1960’s releases of wild-trapped birds. All other populations in Union and Alexander county or extreme western Jo Daviess County are the results of wild-trapped birds released during the period 1982-94 and are not considered established.
  
  
• During the summers of 1991-98 Greater Prairie-Chickens from out-of-state were introduced into Illinois’ only remaining populations in Jasper and Marion counties.
  
  
• The native Wild Turkey population in Illinois was extirpated in the early 1900’s. Turkeys were first reintroduced in the Shawnee Forest in 1959 from out-of-state stock. Once established there, Illinois birds have been and continue to be introduced to unpopulated locations throughout the state.
  
  
• Peregrine Falcon was extirpated as a breeding species; the current breeding population is reintroduced.

Nine other species are known from established in Illinois solely as a result of human introductions: Mute Swan (Cygnus olor), Gray Partridge (Perdix perdix), Ring-necked Pheasant (Phasianus colchicus), Rock Pigeon (Columba livia), Eurasian Collared-Dove (Streptopelia decaocto), Monk Parakeet (Myiopsitta monachus), European Starling (Sturnus vulgarus), House Finch (Carpodacus mexicanus), and House Sparrow (Passer domesticus).

Source:
Illinois Ornithological Society. No date. Birds of Illinois.
http://www.illinoisbirds.org/illinois_list.html