The Willow Warbler is a common small bird, mainly distributed in Asia and Europe. They are one of the most musical birds, and each willow warbler's call is unique.
It is said that the call of the Willow Warbler is known as the "Thirteen Calls" because when the Willow Warbler sings, Typically 13 different tones are emitted. Most of these tones are high-frequency crisp sounds, such as the calls, murmurs, and chirps of warblers. The willow warbler's call is light and beautiful, giving people a pleasant feeling, so it is also one of the most popular birds.