Comparative Analysis of the Alarm Call in Different Age and Sexual Groups of the Russet Ground Squirrel (Spermophilus major Pallas 1778)

The formation of the alarm call's time-frequency characteristics at different stages of individual development was studied on the russet ground squirrel (S. major). The hypothesis about the vocalizations of young individuals of ground squirrels being emitted at lower frequencies than those of adults was tested. The results of the study indicate a differentiated formation of the sound signal in the different sexes of the russet ground squirrel in postnatal ontogenesis. The sound signal in females is formed in the first year of life during the season of activity, whereas it is formed in males in the year following the first hibernation. In terms of the studied call parameters, the voice of adult females is higher than that of young animals of both sexes, while the voice of adult males is lower. The possible causes and significance of the identified sex and age features of the alarm call of the russet ground squirrel are discussed.