OEB Graduate Program Director
Professor of Biology
B.A., Franklin & Marshall College, 1989
Ph.D., Duke Uiversity, 1996
Research in my laboratory addresses the interface of animal behavior, organismal biology, and evolutionary biology. We are particularly interested in a question first articulated by the ethologist Niko Tinbergen: How do proximate mechanisms of behavior, such as biomechanics, physiological performance, and development, shape the evolutionary diversification of behavior? Our work focuses on vocal behavior and evolution in vertebrates, especially songbirds.
Laboratory work aims to characterize aspects of vocal production and perception in songbirds. Experimental studies of vocal learning in hand-reared sparrows are used to assess how limits on vocal proficiency constrain the evolution of vocal frequency, timing, and syntax features. Complementary laboratory activities include quantitative surveys of vocal diversity using bioacoustic analyses, characterization of display motor patterns through high-speed video analyses, and tests of birds' perceptual preferences for songs of varying acoustic structure.
Field work is conducted at local sites, in Brazil, and in the Galápagos Islands. Local field studies address questions of song function and perception in birds. Current research in Brasil, conducted in collaboration with Regina Macedo and her students at the Universidade de Brasilia, addresses questions about sexual selection and communication in a Neotropical songbird, the blue-black grassquit. Work in the Galápagos asks how, in Darwinís finches, the evolutionary diversification of vocal tract morphology has shaped the evolution of vocal proficiency and song structure. The characterization of functional links between vocal tract morphology and song, together with field playback studies, is providing insight into relationships between morphological adaptation, vocal diversification, and reproductive isolation.