Night-Roosting Habitat of Bobwhites

Abstract

A study of the night-roosting headquarters of bobwhites (Colinus virginianus) to determine roosting requirements was conducted in Jackson and Williamson counties, southern Illinois, during December-April, 1953-54, and December-March, 1954-55. Thirty-six coveys and 58 headquarters were included. Sixty-eight percent of the headquarters were on medium or low elevations; 56 percent of the shifts made by bobwhites were from high to medium or low elevations. Sixty-eight percent of the headquarters had good drainage; 60 percent had a southern, and 39 percent a southwestern exposure. Sixty percent of the roosts were on bare ground, 31 percent where only duff was present. Herbaceous plants were most frequently used as roosting cover. Mean height was 59 cm and mean stem density was 16.9 per square foot. The bobwhites showed a strong preference for vegetation with low, sparse, open canopies. The mean light obstruction value of the canopy was 14.3 percent in early winter and 9.3 in late winter. In the 58 headquarters, 65-100 percent of the wind movement was obstructed at ground level; the 2-year average was 92 percent. Covey movements were related particularly to in- creased total daily wind movement and unusually inclement weather. Changes in annual land use result in shifts of roosting areas but not necessarily in reduced populations. Current changes in farming systems reduce the amount of suitable quail habitat. Measures for provision of improved, quail roosting habitat are listed and discussed.