9306688 Randall Striking the hind feet on the ground to create mechanical vibrations has evolved independently in several rodent families around the world. Although foot-drumming behavior is common in desert rodents from North and South Africa, Middle East, Central Russia, Asia, and North America, it has been studied in detail only in the Southwestern United States in the banner-tailed kangaroo rat. Dr. Randall has found that foot-drumming by the banner-tails is part of a communication system: the rats create individually distinct foot- drumming signatures that are used to identify neighbors during territorial defense. She now seeks to understand the evolution of foot-drumming as communication through comparing the banner-tails with three species of kangaroo rat from different locations and habitats. The new species include the giant kangaroo rat, a federally listed endangered species that lives in open grassland, the desert kangaroo rat, which lives in sand dunes, and the Heerman's kangaroo rat from rocky slopes. Of primary interest will be between-species comparisons by age, sex, and individual of the foot-drumming signal in the contexts of territorial defense, competition for resources and mates, and in predator defense. Playback experiments will test for species, sex and individual recognition of identified foot-drumming signals. This is the first comparative study of foot-drumming in closely related species, and as such will contribute to a general understanding of how this unique communication system evolved. Results of this study can help us understand why so many rodents in the world's deserts have evolved foot-drumming behavior. This research should also provide valuable information about desert communities and assist in development of recovery plans for endangered species of kangaroo rats.
