Donald E. Kroodsma is the current reigning authority on the biology of avian vocal behavior, with special reference to its functions, ontogeny, and diversity. He has made major contributions to studies on the neuroethological basis of birdsong and its value as a model for the investigation of vocal learning, and has been a powerful influence in critically evaluating methodologies used in this field.

Among Kroodsma's contributions, many involving students and senior collaborators, are data leading to the discovery of the remarkable correlation between song repertoire size and the parts of the brain known to be involved in song control in different populations of the same species. Other findings in which he has played a key role include the existence in certain warbler species of more than one song type, some of which display learned dialects, and others of which do not; correlations between avifaunal complexity and the size of individual song repertoires; the existence of innate songs in certain primitive passerines; and the puzzling demonstration that song learning appears to take place in castrated male wrens, thus overturning dogma concerning the dependence of vocal learning on testosterone. All these involve issues of broad theoretical importance to the field.

Kroodsma has pioneered studies on the sensitive periods for learning and the fact that they are not fixed but labile, depending on experience and environmental circumstances. With M. Konishi he demonstrated, for the first time, that auditory feedback is not required for normal song development in a suboscine. More recently, he has galvanized the field with compelling claims that some suboscines may engage in vocal learning, presenting a new challenge to neurobiologists.

In addition to the originality of his research, Kroodsma has played an important role in the field as an integrator and in his readiness to work with colleagues to resolve conflicts of interpretation in the field as a whole. In particular, he has fought a long campaign to improve the design of playback studies with birdsong. He has also co-edited, with E. H. Miller, a set of books (Acoustic Communication in Birds, Academic Press, 1982; Ecology and Evolution of Acoustic Communication in Birds, Cornell University Press, 1996) that have provided an integrative forum shaping the development of the entire field.

For his excellence and innovation in the study of avian vocal communication, his scientific rigor and care in evaluating and improving the study of birdsong, and his service to the ornithological community in general, the American Ornithologists' Union proudly honors Donald E. Kroodsma with the Elliott Coues Award for 2003.