THE IMPACT OF CRP ON AVIAN WILDLIFE - A REVIEW

We reviewed the literature to assess the impact of the Conservation Re serve Program (CRP) on bird populations in the central USA. The CRP re placed production agriculture fields with grassland habitat used by mo re than 90 species of birds. At least 42 bird species nested in CRP ha bitats. Bird species richness in CRP fields was similar to Chat in row crop fields, but relative abundance was 1.4 to 10.5 times higher in CR P plantings. Nest abundance was 13.5 times higher in CRP than crop fie lds, although nesting success of songbirds was only slightly higher in CRP fields (40% vs. 36% in crops). Limited evidence suggests that the CRP has positively affected the population growth rates of several no ngame grassland bird species. Waterfowl nest densities and nesting suc cess in CRP fields were similar to those occurring in grassland habita ts managed specifically for waterfowl. The presence of CRP grassland h as been postulated to have improved the quality of existing duck nest habitat by dispersing nests over a larger area. Ring-necked pheasant ( Phasianus colchicus L.) populations seemingly increased substantially with CRP acres. Little evidence of positive population response by nor thern bobwhites (Colinus virginianus L.) to the CRP is available. Over all, grassland birds known to be declining throughout North America we re seemingly the most benefitted by the CRP.