A cuckoo clock is typically a pendulum-regulated clock that strikes the hours with a sound like a common cuckoo’s call and has an automaton cuckoo bird that moves with each note. Some move their wings, open/close their beak whilst leaning forward, whereas in others only the bird’s body leans forward. The mechanism to produce the cuckoo call has been in use since the middle of the 18th century and has remained almost without variation until the present day.
The design of a cuckoo clock is now conventional. Most are made in the traditional carved or chalet style to hang on a wall. In the “traditional style” the wooden case is decorated with carved leaves and animals. They have an automaton of the bird that appears through a small trap door while the clock is striking. The bird is often made to move as the clock strikes, typically by means of an arm that lifts the back of the carving.
In recent years, quartz battery-powered cuckoo clocks have become available. As with their mechanical counterparts, the cuckoo bird emerges from its enclosure and moves up and down, but on the quartz timepieces it also flaps its wings and opens its beak while it sings. During the call the double doors open and the cuckoo emerges as usual, but only on the full hour, and they do not have a gong wire chime.