Brown Thrasher (Toxostoma rufum) Science Article 4
abstract
The role of syringeal muscles in controlling the aperture of the avian vocal organ, the syrinx, was evaluated directly for the first time by observing and filming through anendoscope while electrically stimulating different muscle groups of anaesthetised birds.
Ole Naesbye Larsen and Franz Goller, The Journal of Experimental Biology 205, 25-35 (2002)