Which prairie dog species is noted for alarm calls that distinguish colors of human clothing?

Gunnison's prairie dog is the prairie dog species noted for alarm calls that distinguish colors of human clothing.

The species, Cynomys gunnisoni, lives mainly in the Four Corners region of the American Southwest. Researchers studying its warning calls found that its communication is unusually detailed: calls can vary with the type of danger, and prairie dogs can also distinguish clothing colors and whether a person behaves threateningly or harmlessly.

This does not mean the animals understand color names in the human sense. Rather, their alarm behavior changes in response to visual features associated with particular people or threats. Gunnison's prairie dogs are also credited with up to 11 distinguishable warning calls, making their vocal system a notable example in animal-communication research.

A common mix-up is choosing the black-tailed prairie dog, the best-known species in popular accounts of prairie-dog communication. Black-tailed, Utah, Mexican, and white-tailed prairie dogs are separate species; the clothing-color finding is specifically associated with Gunnison's prairie dog.