©Joseph Tobias

According to Lane et al. 2007 “Mechanical noises have been noted in both species of Cnipodectes. Hilty and Brown (1986: 483) [...]]]> Andrew Spencer recorded for the first time the effect of the twist in the wings of the recently described Rufous Twisting (Cnipodectes superrufus) during a slow wingbeat flight between perches .

©Joseph Tobias

According to Lane et al. 2007 “Mechanical noises have been noted in both species of Cnipodectes. Hilty and Brown (1986: 483) note that C. subbrunneus "can produce a very audible pr’r'r’r'r’r’ in flight with wings." This description is similar to mechanical sounds T.V.H. witnessed, performed by C. superrufus at Kirigueti. In response to playback, Valqui observed the bird approaching aggressively, making an accelerating and decelerating buzzing noise, while flying -4 m off the ground. Although it was not clear what the source of the sound was, it seems likely that it was mechanical and produced by the wings”

You can listen the sound here.