- Boone, Randall B.
University of Maine
Methods used to design and construct the birds and agriculture database are described, and an example of database design is presented using the U.S. Breeding Bird data set. Changes in the frequency of density dependence due to pesticide use, and the correlation of density dependence and r- and K- selection, were determined for 102 bird species associated with agriculture. Evidence exists that density dependence in bird populations is most closely associated with food supply, and that as food supply decreases, the frequency of density dependence increases. Because pesticides can reduce the food supply for insectivorous and herbivorous bird species, I hypothesized that species in areas of high insecticide and high herbicide use more frequently would exhibit density dependence than species in Iow insecticide and low herbicide areas.