Sound Communication of Uinta Ground Squirrels

Abstract

The purpose of this study was to catalog the calls given by Uinta ground squirrels, Citellus armatus, and to determine the cause and function of each. Spectrographic analysis permitted graphic descriptions and quantitative comparisons of the sounds. Records of the behavior of animals before and after each call, as well as the environmental situation, were the basis for determining the causes and functions of these signals. The squirrels produced six different calls: chirp, churr, squeal, squawk, teeth-clatter and growl. They used all the calls in agonistic behavior. An attack, approach or sight of another animal nearby elicited most of the calls. The signals functioned to intimidate others or to inhibit them from moving closer. Squirrels chirped in response to airborne predators and churred in response to ground predators. Spectrographic analysis indicated that these were the same calls the squirrels used in intraspecific threat. Their system of sound communication was simple and unspecific. Its primary use seemed to be as a general attention-getter. Perhaps relying on visual and scent communication and living in relatively open habitat promoted the development of their generalized system of sound communication.