Birds do not make specific sounds to indicate that they are playing in the same way that humans do. Playful behavior in birds often involves physical activities such as flying, hopping, or engaging in mock fights. These behaviors may be accompanied by vocalizations that are similar to their regular calls, but they are not specifically dedicated to indicating playfulness.
Birds have a wide variety of vocalizations that serve different purposes, such as communication, courtship, territorial defense, or warning signals. These vocalizations can include songs, calls, chirps, trills, warbles, and more. The specific sounds produced by birds vary greatly depending on the species and the context in which they are communicating.
While it is difficult to generalize the sounds birds make when they are playing, some bird species are known for their complex and melodious songs, which they use for territorial marking and attracting mates. Examples of birds with notable songs include the nightingale, canary, mockingbird, and many others. However, it's important to remember that birds may vocalize differently when engaged in playful behaviors compared to other contexts.