This research examines the mechanisms and functions of a unique form of communication, never before studied in detail. Dr. Randall is investigating how a nocturnal desert rodent, the banner-tailed kangaroo rat, communicates its identity to other kangaroo rats and protects itself from predators by drumming its hind feet on the ground, creating vibrations that are transmitted both through the ground and through the air. She and her students will (1) describe the basic patterns in the foot- drumming signal and how these identify individual animals, (2) study how the signal is transmitted through the desert soil and air, (3) describe the changes in behavior of rats in response to a foot-drumming signal, (4) study foot-drumming as a defense against snake predators, and (5) analyze differences in the signals produced in relation to the age and health of individual rats, to differences in the number of neighbors' signals, and in contexts of territorial defense, predator defense, and mating competition. This research will enrich our general understanding of how communication is related to the social organization of small, nocturnal mammals. It will contribute to knowledge of how small animals defend themselves against their predators, and of how animal social organizations have adapted to a desert environment. An understanding of the interactions that occur in the web of life in a desert will be valuable in management and conservation decisions about the fragile desert ecosystems of the southwestern United States.
