On the Descriptive Ethology of Richardson's Ground Squirrel

Abstract

Descriptive ethology of Richardson's ground squirrel (Spermophilus richardsoni elegans) was studied for two annual above-ground activity cycles (1967 and 1968). Richardson's ground squirrels studied were located in the Laramie Basin, Albany County, Wyoming. Observed behavior patterns were compared to those of the Uinta ground squirrel (S. armatus) as reported by Balph and Stokes (1963). The postural components of the behavior and circumstances under which these occur appear to be relatively similar between the two ground squirrels. Locomotion, feeding, elimination, grooming, tail-flicking, agonistic, sexual, juvenile behaviors, and general patterns of interspecific behavior seem to be comparable between the two species. However, certain behaviors were noted in Richardson's ground squirrels that were not reported in the Uinta ground squirrel, such a a type of digging and gathering nest materials. Study results showed that relative differences in behavior would probably be more definitive than absolute differences. Richardson's ground squirrel (Spermophilus richardsoni elegans) is sympatric with the Uinta ground squirrel (S. armatus) in southwestern Wyoming (Howell, 1938; Hall and Kelson, 1959). The two ground squirrels closely resemble each other morphologically (Long, 1965). The purpose of this paper is to classify and describe the patterns of behavior observed in the Richardson ground squirrel and to compare these behavior patterns with those of the Uinta ground squirrel as described by Balph and Stokes (1963). The outline and terminology, where possible, follows that of Balph and Stokes (1963), thus facilitating a comparison between the two species. Generally S. richardsoni occurs at lower elevations than S. armatus. STUDY AREA AND METHODS. Richardson's ground squirrel populations were observed in the Laramie Basin, Albany County, Wyoming. The elevation of this area is about 7,200 feet and within what 1 Present Address: Department of Biology, Wisconsin State University, Medford, Wisconsin 54451.