POPULATION TRENDS OF THE HENSLOW SPARROW IN RELATION TO THE CONSERVATION RESERVE PROGRAM IN ILLINOIS, 1975-1995

Data from Illinois' Spring Bird Count was used to estimate long-term p opulation trends of Henslow's Sparrows in Illinois and to examine if t he Conservation Reserve Program has affected these trends. Spring Bird Count data suggest that Henslow's Sparrow populations in Illinois hav e declined significantly over the last 21 yr, with an estimated averag e rate of decline of 7.1% per year between 1975-1995. These data corro borate analyses of other long-term data sets and provide additional su pport for the general impression that populations of this species have declined in many parts of its range. Analyses of the potential benefi ts of the Conservation Reserve Program for Henslow's Sparrows revealed that recent population trends (1987-1995) in counties with high enrol lment in this program were significantly greater than trends in counti es with little Conservation Reserve Program enrollment. Although these data suggest that the Conservation Reserve Program may have benefitte d Henslow's Sparrows in Illinois, this benefit has been insufficient t o offset long-term declines due to other factors. Other conservation a ctions, beyond those associated with efforts aimed at reauthorizing an d improving the Conservation Reserve Program, will likely be needed to achieve adequate protection for this species.