Charles Darwin guessed that the vocal range of a cat amounted to half a dozen different sounds, and professionals today have estimated this range to be from 20 to 600. It has even been suggested that cats have an expressive language, complete with a large vocabulary containing words for “meat”, “mouse” and other important objects in the cat universe.
Probably one of the most distrinctively aggressive cat sounds is the caterwaul. This is usually heard when two rival cats come together, and often signals the beginning of a fight for access to a female on heat. He who growls loudest probably fights hardest, so a weaker cat may actually back off once he hears his opponent’s caterwaul. When this happens, the “lesser” cat’s caterwaul might become more of a gutteral yowl – expressing fear but not necessarily defeat, kind of like saying, “Okay, you win, but don’t cross me again!”