Adam C. Behney
Tamarack State Wildlife Area
The proliferation of invasive, exotic plants has been repeatedly shown to reduce abundance, survival, and diversity of native plants and animals. Cheatgrass (Bromus tectorum) is a non-native, annual grass that rapidly invades disturbed areas and outcompetes native plants to become the dominant species. Areas that have been invaded by cheatgrass offer little heterogeneity in structure or species composition, which many animals, such as northern bobwhites (Colinus virginianus), rely on to satisfy their various resource needs such as food and protective cover, among others. Northern bobwhites are a species of conservation concern in Colorado and require woody cover for resting and protection from predators and harsh weather, areas with forbs and bare ground to produce food and facilitate movement while foraging, and grass for nesting. Cheatgrass outcompetes and suppresses native forbs and bunchgrasses that are used by bobwhites for food and nesting sites.
We will test a cheatgrass herbicide to assess whether it could be a viable habitat management tool for northern bobwhites in northeastern Colorado. Nesting habitat does not seem to be a limiting factor in northeastern Colorado due to the abundance of dense grasses; therefore, our focus is to improve brood-rearing habitat. Furthermore, chick survival is relatively unknown so presenting an estimate of chick survival as well as assessing the effect of habitat use on chick survival would be valuable for identifying population limiting factors. We will monitor bobwhites year-round so if there are impacts of herbicide treatment to other life-stages, we will detect it. This project will provide benefits to management of quail in Colorado by determining if cheatgrass is negatively affecting quail habitat quality, and document whether bobwhites respond positively to the improved vegetation community following cheatgrass removal. We will also estimate bobwhite chick survival, as well as other demographics, that will be used in the future to assess sensitivity of population growth rate to various demographic characteristics.