The Impact of Predators on Quail
Stanley D. Stewart, Wildlife Biologist
The bobwhite has been called a “walking hors d’oeuvre” because it is a prey species for so many animals. Quail experience enormous pressure from predators from the time the chicks are hatched, and even before. In fact, only about one-third of quail nests hatch successfully due to egg-destroying predators. More than half of quail chicks die within two weeks of hatching, mostly from predation. Of those quail that survive until autumn, 80 percent will be dead by the following autumn.
The list of quail predators includes snakes, raccoons, opossums, skunks, armadillos, rats, weasels, squirrels, foxes, coyotes, bobcats, dogs, cats, hogs, turkeys, crows, jays, hawks, owls and ants. Even deer have been documented eating quail eggs. As a general rule, predation by mammals and reptiles is higher during the bobwhite breeding season, and avian predation peaks during winter months of raptor migration and concentration. The list of quail predators is so long that it becomes apparent that predation cannot be eliminated.
Quail exhibit a biological behavior called inversity, or density dependence, a process by which low or highly pressured populations respond with higher than normal productivity. Bobwhites evolved with predators and are equipped with traits that offset predation losses, up to a certain degree. An analysis of the effect of hunting on bobwhite populations indicated that populations can stabilize at different levels across a range of harvest pressures. Hunting is a form of predation, and it is reasonable that natural predation can cause similar controlling effects.
Current research is documenting the effects of predator management on quail populations on sites that are intensively managed for optimal quail habitat in landscapes with high predator populations. Mammalian nest predators, primarily raccoons, opossums, armadillos, bobcats, and coyotes, were removed by trapping during the nesting season for three years from a 2,000-acre study site in northwest Florida. About 300 mammalian predators were removed each year. Bobwhite nesting success nearly doubled, and the fall population of bobwhites tripled. On a nearby control area (same habitat, but no predator management), the bobwhite population increased only slightly during the period. After three years, predator management was discontinued on the test site. One year later, the bobwhite population declined to the level before trapping occurred. The research shows that on sites where excellent bobwhite habitat is provided, nest predator management can further increase quail production, and removal of mammalian predators must be continual to remain effective.
The impacts of predators on quail can also be managed by removing habitats that favor quail predators. Many of the major predators of quail, such as Cooper’s hawks, owls, snakes, raccoons and opossums, utilize hardwood trees for nesting and denning. Mechanical removal of canopy level and mid story upland hardwoods on quail research sites in southwest Georgia resulted in dramatic improvements in adult bobwhite survival, nest production, nesting success, and quail brood survival.
Predator control is not the first step toward improved quail populations. Habitat management that supplies abundant nesting cover, brood habitat, and protective cover is fundamental. If habitat is good, predator management can carry quail populations to higher densities.