A bird sound I would be interested to hear: the Club-Winged Manakin (Machaeropterus deliciosus) of the Ecuadorian rain forest produces a sound described as "two sharp clicks followed by a sustained, violin-like note." The phenomenon was observed by Darwin the 19th century, but only now does Kimberly Bostwick of Cornell offer an explanation. Male birds strike their wing feathers behind their backs more than 100 times a second (faster than the wingbeats of hummingbirds), and (it is hypothesized) rub together two opposing feathers with specialized ridges on the shafts. "[A] feather rubs against about seven ridges on the way out, and about seven on the way back," producing the characteristic 1500Hz tone.

posted: 9:55:17 AM  

There is a House Sparrow (Passer domesticus) nest somewhere outside my office window (likely, lots of them, given the looks of the neighborhood), and I can hear a trickle of "chewp...chewp.....chewp...chewp"—wee birds begging for food. About once every two seconds, not regular, not irregular, just incessant. Believe me, if the Party ever takes me to Room 101, all they'll need to do to break me is to play a stream of insipid chirps from a House Sparrow.

posted: 9:55:16 AM