OPERATIVE TEMPERATURE REDUCES HABITAT SPACE FOR NORTHERN BOBWHITES

High operative temperatures may cause wild animals to avoid habitat sp ace-time, leading to thermal fragmentation of habitat. We evaluated th ermal fragmentation of habitat space for northern bobwhites (Colinus v irginianus) in a subtropical-subhumid portion of Texas during June 199 4-August 1995. Based on data from 606 random points, 405 flushing poin ts, and 237 landing points, bobwhites avoided habitat spacetime with o perative temperatures >39 degrees C during the hottest period (Jul-Sep ). The estimated proportion of habitat space-time avoided exceeded 0.5 0 during all seasons and reached maximums of 0.65 for flushing points (Mar-Jun) and 0.74 for landing points (Jul-Sep). Habitat management th at fosters lower operative temperatures near the ground may increase t he abundance of bobwhites in tropical and subtropical environments.