Sexual selection and mate choice: Songbirds (suborder Passeri) are one of just a few animal groups with imitative vocal learning. The fact that birdsong is learned early in life makes it particularly rich in information content. By attending to the song of potential mates and territorial rivals, birds can obtain useful clues as to the singer's past and current condition, level of motivation, and place of origin. My students and I are particularly interested in whether song serves as a cue to promote or avoid inbreeding.
Host-parasite interactions: Parasites represent nearly half of all species and have important effects on host fitness. We are investigating whether parasites become locally adapted to their hosts or vice versa, and by extension, how parasites affect the evolutionary trajectories of their songbird hosts.