Birds are known for their wide variety of vocalizations, which can be broken down into several categories. CHIRPS, TWEETS, coos, caws, and twitters are all examples of bird sounds. CHIRPS are short, high-pitched sounds made by many small birds. TWEETS are similar to CHIRPS, but are slightly longer and more complex. Coos are low-pitched, repetitive sounds made by doves and pigeons. Caws are loud, harsh calls made by crows and ravens. Twitters are rapid, high-pitched sounds made by many species of birds.