Dr. Kroodsma will carry out four interrelated studies of vocal development and its consequences among passerine (perching) birds. These four developmental studies are important for understanding the neural control, the evolution, and the functions of acoustic signals among birds. 1. In contrast to true (oscine) songbirds, flycatchers seem to lack the ability to imitate vocal signals. Comparison of song development by (suboscine) flycatchers and by oscine songbirds is a critical first step to understanding the consequences of strikingly different modes of song development and the possible differences in the neural control of vocal signals in these two suborders of passerine birds. 2. Laboratory experiments on song development with towhees will reveal the processes by which interacting birds develop songs that are either similar or dissimilar to those in their acoustic environment. 3. Paruline warblers use different songs in different contexts. Studies of their song systems will help in understanding the relationship between vocal development and geographic variation in songs, the selective forces on the structure of acoustic signals, the responses of males and females to these songs, and how warblers use this remarkably complex communication system. 4. A study of wren vocal behavior will examine the possible role of song development and cultural evolution in maintaining genetic isolation between two song populations in an area that they both inhabit. To do this research, Dr. Kroodsma relies on a combination of field and laboratory studies, and chooses the most suitable species for each set of questions. The results should yield important insights into the relationship between song development and the functions of vocal behaviors of birds.
