USE OF HELICOPTERS TO SURVEY NORTHERN BOBWHITE POPULATIONS ON RANGELAND

Northern bobwhites (Colinus virginianus) and white-tailed deer (Odocoileus virginianus) are of management importance throughout south Texas (Guthery 1986:157). Harvest management procedures vary greatly; however, deer management usually includes a fall helicopter survey to determine herd characteristics for harvest prescriptions. During these surveys, coveys of bobwhites are often seen and recorded, but the data are unused in management because of untested bias and precision. Lehmann (1984:111) mentioned using a helicopter to survey bobwhites and Attwater's prairie-chickens (Tympanuchus cupido attwateri) but did not discuss details. We examined the use of line transects conducted from a helicopter to estimate bobwhite density. Our objectives were to detemine if (1) helicopter speed or altitude affected quail counts, (2) unbiased estimates of bobwhite density could be derived from helicopter counts, and (3) helicopter counts were economically feasible compared to 2 other methods of density estimation.