The diversity of bird songs is astonishing and poses a significant puzzle from both aesthetic and scientific perspectives. Evolutionary biologists still do not understand why bird song is so inventive and why numerous bird species spend so many hours singing. The commonly suggested explanations—territorial defense and attracting mates—fail to account for the variety and energy displayed by many familiar birds. Do birds perhaps sing simply because they enjoy it? This seemingly naive explanation is increasingly emerging as the truth. "Why Birds Sing" sensitively explores the reasons behind bird song—following in the tradition of classic works by authors like Bernd Heinrich—and combines the latest scientific research findings with a profound understanding of beauty and form.