Very interesting research highlighting the source of the whistle we hear when pigeons are startled and take off. This novice always assumed the whistle to originate in their vocal chords. I've often thought of it as I listened to them take off, even when I thought they "shouldn't" be startled by my approach. Check this out:
Quoting:
Startled Pigeons Whistle With Their Wings, Michael Reilly, Discovery News: Sept. 2, 2009 -- Startled pigeons give off a shrill, rattling whistle when they take flight that signals the flock to scatter, according to a new study. But it doesn't come from their mouths; a specially-evolved wing feather seems to be the noise-maker, vibrating to sound the alarm.
See the research article here: http://dsc.discovery.com/news/2009/09/02/pigeon-wing-alarm.html
Amazing! Who would have guessed?
Linda