Nest success and brood habitat selection of the northern bobwhite in Southeast Iowa

The northern bobwhite (Colinus virginianus) is one of the most popular upland games species in North America, and in turn has been a focus of game management and research from as early as the 1920s. However, bobwhite populations continue to decline throughout their geographic range. The cumulative effects of advanced succession and monoculture farming are often cited as a primary cause of range wide declines. As productivity may be one of the most important factors associated with changes in population size, identifying and managing quality nesting and brood habitats is vital to reversing the steady downward trend in bobwhite populations. In 2003 and 2004, we compared nest success and brood habitat selection of radiotagged bobwhite between a managed and unmanaged (private) landscape in southeastern Iowa. Using program MARK, we estimated daily nest survival with the best approximating model that included an area and year effect only. The daily survival rate in 2003 was higher within the managed area (managed: 1.00, SE = 0.00; private: 0.953, SE = 0.023), whereas 2004 daily survival rates were similar between sites (managed: 0.969, SE = 0.011; private: 0.964, SE = 0.011). Microhabitat characteristics, landscape composition and configuration within 210 m of a nest, and applied management techniques did not have a measurable effect on nest success. At both the home range and patch scale, broods on the managed and private study areas used habitat types differently. At the home range scale, broods on the private area simply selected for all habitat types not in row crop production, while broods on the managed area selected for habitats with early successional habitat characteristics and showed an avoidance of timber patches. At the patch scale, broods 2-weeks of age on the managed area selected for early successional habitats. At 4 weeks of age, broods showed only an avoidance of timber patches. There was no statistical evidence for brood habitat selection at the patch scale on the private study area. The percent of forb canopy cover within a habitat patch was a significant predictor of brood use, as were fields burned the previous year