Nest predation ecology of the northern bobwhite in the southeastern USA

Abstract

Predation is a natural process in ecosystem ecology; however, many ecosystems have undergone tremendous alterations as a result of human impacts. Thus, the process of predation is often altered greatly and requires extensive reevaluation in light of modern landscapes and societal values. Nest predation is considered the leading cause of nest failure for most avian species, including the Northern Bobwhites (Colinus virginianus), and may have the potential to limit bobwhite populations. Understanding these predator-prey dynamics requires knowledge of the interactions among predators, prey, and the environments at which they coexist. I report a portion of the findings of a large-scale collaborative study conducted in the southeastern United States to examine the influence of predators on bobwhites population demographics. The objective of this study was to assess the complex nest predation processes through simultaneous study of the meso-mammalian predators and bobwhite nesting. My results suggest that sources of nest mortality by different predators are at least partially compensatory. As nest predation by one guild decreases, other failure causes increase to fill the void. Landscape features appear to influence the predation process more at larger scales (> 50 ha) than smaller scales (< 20 ha) with fallow and annually disked fields being important features of the landscape decreasing nest failures. I found nest predation to be incidental and that fate of a nest was independent of the fate of neighboring nests. My results demonstrate the influences of the first extensive study on quantifying the influence of intensive meso-mammal predator control on predator demographics. Predator control, as done in this study, was intensive enough to meet management objectives of reducing predator use at the local scale, while maintaining predator presence on the greater landscape. Extensive reevaluation of predators, prey, and alternative prey interactions with the modern landscape will be required in order to better understand the predation process in the future.