Many animals have geographic variation or dialect differences in their vocalizations. These differences combined with social behavior and isolation can contribute to speciation. We compared the acoustic vocalizations of 3 subspecies of Spermophilus lateralis and those of S. saturatus using wild-caught animals in the presence of a predator, Canis lupus familiarus. Variation was examined using 9 sonogram variables. We found both local dialect differences and geographic variation in alarm calls. S. saturatus could be distinguished 100% of the time from S. lateralis using discriminant analysis. Widespread use of ultrasonic vocalizations was found in both S. lateralis and S. saturatus. Dialect differences showed a pattern of character displacement between adjacent subspecies. Vocalization parameters changed within local sites and between years, suggesting alarm calling is at least partially a learned behavior. Species share more uniquely defining vocalization variables than either subspecies or local populations.