I study patterns and processes of avian diversification. I have broad interests in all levels of diversity across the globe, from higher-level systematics to intra-specific diversification processes, and I work on projects that span this continuum of evolutionary history. I focus on insular systems, where I combine specimen-based field work with molecular phylogenetic/genomic techniques to examine the tempo and mode of rapid geographic radiations across the Pacific. Museums are a major component of my research and I dedicate significant portions of my time to growing and curating natural history collections, including an active field program