Nightingale (whistle)

Nightingale. Hold the metal ring with one hand, and turn the wooden piece with light pressure using the thumb and index finger on the other hand. If you simulate the nightingale’s song, you need to turn the wooden piece with variation and at different speeds in both directions. Don’t use too much force.
See video below. 
Delivered in handmade wooden box.

Video: French Francois Morel shows here how the bird sound is produced. Francois Morel is an ornithologist and has been producing bird calls since 1975. Read more about the production of bird whistles.