Birdcalls are the vocalizations made by birds to communicate with each other. They can be used for a variety of purposes, such as finding a mate, warning of danger, or simply expressing joy. Birdcalls can be divided into two categories: NOTES and pipes. NOTES are short, melodic sounds that are often repeated in a pattern, while pipes are longer, more complex calls. NOTES are usually made by smaller birds, while pipes are typically made by larger birds.