When Professor Con Slobodchikoff of Northern Arizona University first started studying prairie dogs 30 years ago, he couldn't tell the difference between warning calls for different predators. However, the prairie dogs all responded to what appeared to be similar calls with different specific behaviors, like scurrying into their burrows for cover or standing up to get a better view. Slobodchikoff began to think there was something to the sounds that he wasn't hearing.
Slobodchikoff and his students recorded the noises from prairie dog villages whenever a human, dog, coyote or hawk passed. Then he used a computer program to analyze the recordings. The program measured the calls' frequencies and separated out the component tones and overtones.
What Slobodchikoff discovered was that the calls clustered into different groups, and each cluster had its own signature set of frequencies and tones. Prairie dogs, in other words, don't just have a call for "danger" — they have one call for "human," another for "hawk" and a third for "coyote." They can even differentiate between coyotes and domesticated dogs.Even more astonishing, upon further analysis he discovered that prairie dogs appear to have methods of describing individuals within each type of predator. He had four volunteers walk through a prairie dog village dressed exactly the same except for their shirts. Each volunteer walked through the communities four times: once in a blue shirt, once in yellow, once in green and once in gray.
He found, to his delight, that the calls broke down into groups based on the color of the volunteer's shirt. "I was astounded," says Slobodchikoff. But what astounded him even more, was that further analysis revealed that the calls also clustered based on other characteristics, like the height of the human. "Essentially they were saying, 'Here comes the tall human in the blue,' versus, 'Here comes the short human in the yellow,' " says Slobodchikoff.Slobodchikoff's experiments have been repeated with other groups of prairie dogs. His experiments offer insight into other highly social animals that may communicate with languages more sophisticated than we expect.
Source: New Language Discovered: Prairiedogese - NPR
Sara Duane-Gladden is a freelance writer in the Twin Cities area of the great state of Minnesota.
