A macaw demonstrated that she has learned language. Evidence from recordings is presented in the book with some recordings posted on the book Internet page.
Arielle is a macaw, a type of talking bird. She has learned more than 6000 expressions.
No technical knowledge is required to understand the material, as the author walks readers through the sonic communication process. He explains linguistic principles, and provides easy-to-understand examples to make points.
In the end, we might think birds are better at language than many humans.