AUTUMN AND WINTER BIRD POPULATIONS IN HERBICIDE-TREATED CROSS TIMBERS IN OKLAHOMA

Birds were counted during autumn and winter from October 1987 through February 1989 on sites in Cross Timbers in central Oklahoma 5 and 6 yr after herbicide treatments. We censused two replications of tebuthiuron-treated, triclopyr-treated, and untreated reference sites with a modification of the point-count method. Thirty-five species were documented during the entire census period; 16 species were observed only on herbicide-treated sites and two species only on reference sites. During autumn and winter, more birds and more species were found on sites treated with herbicides than on reference sites. Tebuthiuron- and triclopyr-treated sites supported similar numbers of species during both seasons. Herbicide-treated sites had the highest species richness, but untreated areas were needed to maintain interior woodland species.