|Greater Prarie-Chicken Relative Abundance Map|
|Source: North American Breeding Bird Survey (BBS)|
This map indicates the average count of Greater Prarie-Chicken in the U.S. The Greater Prairie-Chicken is closely associated with the native prairies of eastern and central North America. These native prairies have largely disappeared, causing a dramatic reduction in this species' abundance and range during historic times (Christisen 1969, Hamerstrom and Hamerstrom 1961). The isolated eastern race became extinct in 1932. Elsewhere east of the Mississippi River, populations fluctuated during the twentieth century but are currently reduced to a small remnant flock in south-central Illinois (McPeek 1994). The race in Texas has also been reduced to very small numbers. The only sizable populations remain on the Great Plains, where the species has almost completely disappeared from Canada and dramatically declined elsewhere along the northern edge of its range (Godfrey 1986, Stewart 1975).
Sauer, J. R., B. G. Peterjohn, S. Schwartz, and J. E. Hines. 1995. The Grassland Bird Home Page. Version 95.0. Patuxent Wildlife Research Center, Laurel, MDCautions for this Product:
As is true for other grouse, Greater Prairie-Chickens are poorly surveyed by the BBS (Sauer et al. 1994). The surveys are conducted after the males have abandoned their leks, and most records are chance sightings of individuals or hens with broods. Since this species is found along a very small number of routes, the scattered records may not be representative of the actual population trends. For example, the BBS data show no significant trends during 1966- 1994. Because of the small sample sizes, the trend estimates for the other intervals are of very questionable validity. However, the survey-wide indices exhibit a general decline throughout the survey period, which is probably more representative of the actual population trends. These declines are most apparent in Kansas and western Missouri. While Greater Prairie-Chickens are recorded in small numbers along most BBS routes in their range, they are most numerous in Kansas.
Analysis and interpretation of BBS data is tricky, because the survey incorporates information from a huge geographic area and the survey varies greatly in quality of information over the area. To document some of the problems with the analyses of BBS data, and help interpret the results presented, a series of help files is provided with information on the survey, discussion of problems with analysis, and details on how the presented information should be interpreted.
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