Referential specificity in the alarm calls of the black-tailed prairie dog

In this study, we show that black-tailed prairie dogs (Cynomys ludovicianus) have a referential system of communication, i.e., their alarm calls have specificity for different characteristics of humans. In a series of experiments, we tested the ability of black-tailed prairie dogs to encode information into their alarm calls about the color of clothes and general shape of humans who were potential predators. We also assessed the information encoded into the alarm calls elicited after a human fed the prairie dogs, and after a human shot a weapon within the colony. The results show that black-tailed prairie dogs have a referential communication system similar to that described for Gunnison's prairie dogs, with qualitatively and quantitatively different alarm calls for different predator characteristics.