WILL CONVERSION OF CONSERVATION RESERVE PROGRAM (CRP) LANDS TO PASTURE BE DETRIMENTAL FOR GRASSLAND BIRDS IN KANSAS

The Conservation Reserve Program (CRP) was established by the 1985 Foo d Security Act (Farm Bill). Unless renewed, most CRP contracts will ex pire in 1997 and up to 70% of CRP fields in Kansas may be converted to pasture. We compared avian use of CRP areas with that of pasture to d etermine if such conversion would be detrimental to grassland birds. D ata on vegetative structure, avian abundance, and avian reproductive s uccess were collected on five CRP fields and five pastures during summ er 1993. Pastures had significantly greater vegetative cover and CRP f ields had more bare ground. Vegetation was significantly taller in CRP fields late in the summer. Total avian abundance and that of dickciss els, grasshopper sparrows, meadowlarks, brown-headed cowbirds and upla nd sandpipers were greater in pastures than in CRP fields. Reproductiv e success and rates of nest parasitism by brown-headed cowbirds did no t differ between the habitats, but nests were more numerous in grazed pastures. If the CRP is not reauthorized in the 1995 Farm Bill and mos t of the Kansas land currently enrolled in CRP is converted to pasture , the conversion probably will not be detrimental to grassland bird po pulations if the land is moderately grazed.