Bird calls are the sounds that birds make to communicate with each other. These calls can serve various purposes, such as attracting mates, signaling danger, or marking territory. Each species of bird has its own unique set of calls, which can vary in pitch, tone, and rhythm. Bird calls can be simple, like a single note, or complex, involving a series of sounds. Some birds, like songbirds, are known for their melodious tunes, while others, like crows, may produce harsh, cawing sounds. Understanding these calls can help birdwatchers identify different species and their behaviors.