Movements, habitat selection, and survival of northern bobwhites in response to disturbance during field trials

This study evaluated the effects of field trial disturbance on northern bobwhite quail (Colinus virginianus) with respect to 1) survival, 2) movements, and 3) habitat utilization on Ames Plantation in western Tennessee. A total of 81 bobwhites in 20 coveys was monitored via radio-telemetry on 3 study areas in late winter (January 9 - April 1) during 1995 and 1996. Each year, bobwhites on the Morning Field Trial Area (MFTA) and the Evening Field Trial Area (EFTA) were subjected to 2 weeks of disturbance in mid-February produced by bird dog field trials. Bobwhites on the Control Area (CA) were not exposed to field trial activities. Though late winter survival was higher in 1995 (0.944, n=36, SE 0.040) than in 1996 (0.728, n=45, SE 0.068) (p < 0.05), survival was unaffected by disturbance as estimates did not differ significantly among study areas in either year (p > 0.05 in all cases). Mean hourly movement during the study was 37.1 m (SE 1.2 m), but differed among study areas and between years. Hourly movements were greater in 1995 (40.8 m, SE 1.4 m) than in 1996 (29.2, SE 2.2 m). Hourly movements on MFTA (48.3 m, SE 2.6 m) were greater than on EFTA (35.3 m, SE 6.6 m). Hourly movements were lowest on CA (29.5 m, SE 1.8). On average, coveys on MFTA retreated 62.3 m (SE 17.5 m) from the field trial course during periods of disturbance. On EFTA, coveys retreated 25.1 m (SE 6.6 m). However, movements were not great enough to remove bobwhites from their home ranges. Multiresponse permutation procedures revealed that 18 of the 20 coveys made spatial adjustments within their home ranges during late winter. Disturbance was not the sole factor influencing bobwhites, as adjustments occurred on CA, as well as on MFTA and EFTA. Analyses of habitat utilization revealed that bobwhites changed their utilization of available habitats in only 2 of 6 cases. With few exceptions, analyses of habitat selection comparing use and availability revealed that bobwhites used partially-stocked stands more than expected and agricultural fields less than expected.