Impacts of predation on northern bobwhite and scaled quail
Copyright 2001 The Wildlife Society. Used by permission.
Northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) populations have declined throughout most of their distribution, and these declines have become more dramatic in recent years. In this review, we examine the role of predation in quail management. Predation is the major source of nest loss and of mortality for young and adult quail. Mean nest success across studies reviewed was 28%. Estimates of annual survival rates have varied from 5 to 26% for radiotelemetry studies and from 15 to 30% based on age-ratio studies. Breeding season survival estimates ranged from 13 to 51% in telemetry studies reviewed. Brood survival is the least studied aspect of quail survival; estimates ranged from 13 to 47%. Mammalian predators most often implicated in nest predation include striped skunks (Mephitis mephitis), raccoons (Procyon lotor), opossums (Didelphis virginianus), foxes (Urocyon cinereoargenteus and Vulpes vulpes), coyotes (Canis latrans), and feral hogs (Sus scrofa). Accipiters (Accipiter spp.) and northern harriers (Circus cyaneus) are the most common avian predators of quail. Less information is available to assess impact of predation on scaled quail, but observations from areas where bobwhites and scaled quail are sympatric suggested that scaled quail are less vulnerable to predation than bobwhites. Although quail have adapted to cope with high predation rates (e.g., renesting, large clutches), populations in some areas may be suppressed by predation. Changes in land use, management practices, and predator communities interact to depress quail populations over much of the bobwhite's range. Additional studies are needed to assess the role of predation and predation management in light of these landscape-level changes. A variation of the Integrated Pest Management philosophy used in crop production is proposed as an appropriate model to address predation management for quail.