Acute Impact of Herbicide Strip Treatment on Mixed-Brush White-tailed Deer Habitat on the Northern Rio Grande Plain

Abstract

White-tailed deer tended to evacuate a 1,800-ha, mixed-brush pasture during 5 months following aerial strip-spraying in May with 2,4,5-T + picloram (1:1) at 0.56 kg/ha and 1.12 kg/ha and in two widths (80% coverage). Deer were attracted to the pasture in above-normal numbers the following winter but their numbers returned to normal by 11 months posttreatment. Apparently, succulent woody plant regrowth provided an attractive food base which induced the posttreatment increase in numbers. Deer on the pasture did not rearrange their use to favor untreated brush as a response to treatment rate or width of treated strip. Woody plant canopy cover was significantly reduced on all treated strips but cover screen at deer height was unaffected. Evidence suggests that only the high rate of herbicide application resulted in significant reduction in the stature of brush. Density of live brush stems was reduced less than 20% by treatment.