|Abstract or Summary
- Short-term effects of 3 grazing systems and prescribed burning on bobwhite (Colinus virginianus) populations were investigated on the Welder Wildlife Refuge near Corpus Christi, Texas, during spring (April through June) and fall (September through October) of 1976 and 1977. Two rotational systems, high intensity-low frequency (HILF) and four-pasture, deferred-rotation (4PDR), and a continuously grazed system (CONT) were initiated in 1975. Prescribed burning was executed in December of 1975. Each of the grazing systems was represented by 1 pasture; 2 study areas (16 ha each) were selected within a pasture. Two burned areas (12 ha each) and an unburned area (12 ha) were located in a 4PDR pasture. On all 9 study areas, herbaceous cover (grass, forb, dead and bare ground) by life form was sampled with a point frame. Quail population indices were determined from 4 methods: number of quail observed along transects, trapping success, flush censuses, and total number of calls recorded ("bob-white" in spring and roost call in fall). During the spring of 1976, significantly more "bob-white" calls were recorded in HILF than in the other 2 systems (P=0.024). Remaining comparisons of population indices did not yield significant differences among the 3 grazing systms. Nevertheless, a trend developed in which quail used the HILF most frequently and used the 4PDR least often. Preference for the HILF pasture probably occurred in response to the small amount of grass cover, relatively large amounts of bare ground and forb cover, particularly of a tall life form. As a result, long-term research is necessary to determine the effects of grazing systems on vegetation and therefore, on quail populations. After winter burning, significantly more "bob-white" calls (P<0.05) were recorded on the burned areas than on the unburned area during the spring of 1976. Significantly more (P<0.05) bare ground existed on the burned areas than on the unburned area during 1976; however, no significant difference in herbaceous cover occurred between burned and unburned areas during 1977. In response to this vegetative change on burned areas, significant decreases (P<0.05) in the number of quail flushed occurred from 1976 to 1977. No significant changes in quail use occurred on the unburned area between 1976 and 1977. The transitory effect of prescribed burning appeared beneficial to bobwhites, an early successional species. Therefore, a viable bobwhite management program may involve frequent burning, provided ample rainfall is available.