Prairie dog calls encode predator details
Con Slobodchikoff's research on Gunnison's prairie dogs found that their alarm calls change with the kind of predator and also carry details such as a human's size, the color of their clothing, and how fast they are moving. The calls behave like descriptive nouns and modifiers rather than simple fear cries. The case shows that a rich, referential system can go unnoticed when researchers assume in advance that animals only express emotional states.