Grassland bird associations in a managed agricultural matrix by Ross Robert Conover A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Animal Ecology Program of Study Committee: Stephen J. Dinsmore, Major Professor L. Wes Burger, Jr. Rolf R. Koford Diane M. Debinski Thomas M. Isenhart Iowa State University Ames, Iowa 2009 Copyright © Ross Robert Conover, 2009. All rights reserved.