“…Each site was located in active corn or soybean fields, which have comparable visibility. Topographic settings were similar, as each site was located on top of a natural levee in the floodplain of the Site files Barnette, 1978Barnette, 1978Barnette, 1978 Site files; Barnette, 1978Barnette, 1978Woodall, 1990Woodall, 1999 Site Barnette, 1978Woodall, 1984 Site files Site files; Barnette, 1978 Site files; Barnette, 1978 Site files; Barnette, 1978Barnette, 1978Barnette, 1978Barnette, 1978 Site files; Barnette, 1978Barnette, 1978Barnette, 1978 Site files…”