Northern Bobwhite Habitat Requirements and Evaluation Guide
The northern bobwhite (Colinus virginianus, hereafter bobwhite) is a well-known and widespread upland game bird found in the eastern half of the United States. The bobwhite is particularly common in the southern Great Plains and its numbers are directly related to land use, management practices, and weather. Recently, bobwhite populations have been on a steady decline throughout much of its range, with an average annual decline of 2.0% in Oklahoma (30). Specifically, bobwhite habitat has been impacted by farming, conversion of native plant communities to introduced forages, fire suppression, forestry practices, and urban sprawl. In rangelands, heavy grazing and herbicide use have reduced the diversity of native plants that bobwhite require. In forests, the lack of both fire and tree thinning have reduced herbaceous and shrub cover that bobwhite require (27). Conversion of native plant communities to pastureland dominated by monocultures of introduced grasses has also eliminated habitat for bobwhite, as has the industrialization of rangelands for energy production.
Outside of habitat requirements, weather also plays an important role in abundance of bobwhite in the southern Great Plains. Specifically, temperature and precipitation influence the ecology of bobwhite (16, 23), especially in the breeding season. Less precipitation has been linked to shorter nesting seasons and fewer nesting hens, which in turn results in lower juvenile:adult ratios the following hunting season (18). Furthermore, bobwhite are very sensitive to extremes in temperatures (12), and abundance of bobwhite has been shown to be influenced by summer temperatures (23).
The purpose of this guide is to provide a means to systematically evaluate the suitability of habitat for bobwhite. The guide can also be used to evaluate non-native vegetation such as introduced pasture or cropland. It is designed to allow you to inventory existing habitat conditions and to determine what the limiting factor(s) are that keep bobwhite numbers below the potential of the land and climate. The limiting factor(s) are those elements that are limited in occurrence or missing. Those limited or missing elements must be improved or developed before the land becomes usable by bobwhite.