Land use and pheasant habitat in north-central Iowa, 1938-1973

Land use changes and the consequent effects on ring-necked pheasant (Phasianus colchicus) habitat from 1938 to 1973 were analyzed on four 2-section sample units from each of 27 counties in north-central Iowa using sequential aerial photography and annual Iowa crop reports.Though the total percentage of land used for agriculture remained near 89 percent, there was a major shift in land use from small grains, hay, and pasture to corn and soybeans.Row crops increased from 32.5 percent of the land area in 1939 to 58.4 percent in 1972, primarily because of a ten-fold increase in soybean area.Small grains, hay, and pasture together comprised 55.5 percent of the land area in 1939, but only 11.7 percent in 1972.Oats, hay, and pasture, respectively, declined 82.6, 55.6 and 63.0 percent.Land in federal retirement programs occupied 10 to 12 percent of the land area after 1965.Nonagricultural land use changes were significant, though individual categories never comprised large percentages of the land area.Area in wetlands, undisturbed grassland, fencerows, and farm groves, respectively, declined 55 percent, 71 percent, 31 percent, and 13 percent from 1939 to 1972, while area in drainage ditches, roads, and roadsides increased 45 percent, 25 percent, and 24 percent.All pheasant nesting habitat declined only 44 percent, while nesting cover from which high production was expected declined 76 percent, from 30 percent of the land area in 1939 to 7 percent in 1972.Reductions of area in oats, clover, wetlands, and undisturbed grassland viii were primarily responsible for reduction of good pheasant nesting cover.Winter cover declined 33 percent, from 2.6 percent of the land area in 1939 to 1.8 percent in 1972, primarily because of reduced area in farm groves and wetlands.Management of roadsides, railroad right of ways, wetlands, undisturbed grassland areas, and grassed waterways are necessary to provide the quantity and quality of habitat required to produce more pheasants in north-central Iowa.