Project Leader:
darcy kelley
(dbk3@columbia.edu)
Martha Tobias
(mt18@columbia.edu)
Additional External Researchers:
Martha Tobias, mt18@columbia.edu
Bill Klemens (CERC, Wildlife Conservation Society)
Chris Raxworthy (CERC, American Museum of Natural History)
Locations: Gabon, South Africa
Description:
THE RESEARCH FOCUS
Social communication is ubiquitous in animals; even the most solitary species meet to mate. Dedicated sensory, neural and muscular systems support social communication. Examining these systems enables us to learn how one brain communicates with another.
The forms of communication - sound, smell, sight- are determined by a species' habits and its habitats. We study vocal communication, a form used by a number of species including our own. Vocal signals have a number of advantages for communication. Reception of the signal does not require a specific orientation and does not depend on time of day. Within the acoustic channel, information can be carried by a number of sub-channels that include sound frequency (or pitch), sound intensity (or loudness) and the temporal patterns of sounds. Vocal communication also poses some steep challenges as even a brief consideration of human speech reveals. A simpler example is sound localization. Where the sound is coming from and how it is moving must be calculated from many ambiguous information sources. Nonetheless, perhaps because locating the sound source is fundamental to social communication, many species have developed highly effective mechanisms to home in on (or avoid) a vocal signaler or a sound source (such as a predator).
Courtship songs provide powerful examples of vocal communication. It has even been argued (Miller, 2000) that human language evolved from the songs sung by men and women to each other that demonstrated attractive qualities as potential mates. We study the South African clawed frog, Xenopus laevis, a species with a particularly rich vocal repertoire. Females sing to males, males to females and to other males and many of these signals are specific to the sex of the signaler, the recipient and the social context. Our goals are to determine how these vocal signals are produced and responded to. The prominent role of songs in X. laevis and the ease with which certain aspects of song production can be studied should provide fundamental insights into how the brain translates what is heard into what is uttered. Because songs are specific to sex, both in terms of the signals themselves and the social context in which they are produced, we also wish to determine how vocal communication becomes sexually differentiated.
EI Unit:
Center for Environmental Research and Conservation (CERC)
Cross Cutting Themes:
Ecosystems
Core Disciplines:
Biology
Collaborating Institutions:
University of Geneva in Switzerland
University of Bristol in the UK and McMaster University, Canada.
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