Title: Conserving Avian Diversity in Agricultural Systems: the Role of Isolated

Over one third of the earth’s land surface has been modified to some extent for agricultural purposes. The large global footprint of agriculture, combined with the knowledge that existing reserve networks are likely insufficient for long-term conservation of native biodiversity, has necessitated that agricultural systems contribute to conservation of native biota. Current research paradigms have taken a landscape-level view of conservation in agricultural systems, assessing the relative contribution that various habitat elements make in conserving biodiversity in the agricultural matrix. Within this context, I investigated the potential role that individual Oregon white oak (Quercus garryana) trees play in conserving avian diversity in the agricultural systems of the Willamette Valley, Oregon, U.S.A. Retained by landowners primarily for cultural reasons, many of these trees pre-date Euro-American settlement of the Willamette Valley and thus are biological legacies from historic white oak habitats. I compared avian use of isolated white oak trees in three different site contexts- croplands, pastures, and oak savanna reserves- and used an information-theoretic model selection approach to determine the relativ