Bushtit
Chapter 6: Song Learning Often Creates Complex Songs and Large Repertoires
Subchapter: What? "Songbirds" with no song?
From page 107 in the book.
Photo by Brian E. Small
♫456. The tsit call, so simple, though it can vary in loudness, duration, emphasis, and so on. March 9, 2017. Montaña de Oro State Park, Los Osos, California. (1:01)