The Red-winged Blackbird (Agelaius phoeniceus), Yellow-headed Blackbird (Xanthocephalus xanthocephalus), and Common Grackle (Quiscalus quiscula) are the three most abundant blackbird species (Icteridae) found in North Dakota and comprise almost 10% of its avian population (Stewart and Kantrud 1972). Blackbird abundance combined with their food habitats make them significant agricultural pests on sunflower. Cost estimates for blackbird damage to sunflower in the North Dakota are likely over $10 million dollars annually (Kleingartner, pers. comm). Because of this economic impact blackbirds have on agriculture, it is important to understand land use and climatic factors influencing blackbird abundance. This study will compare route-level and finer-scale summaries of stop-level resolution to determine which scale is most effective for creating blackbird abundance models from land use and climate data. This additional resolution of analysis will potentially improve the fit of blackbird abundance models by providing additional information that may be missed in larger scale analyses.
Available at: http://works.bepress.com/george_m_linz/3/