Birds produce a variety sounds to communicate with flock
members, mates (or potential mates), neighbors, & family
members. These sounds vary from short, simple call notes (and
short, simple songs like those of Henslow's Sparrows) . . . . .
. to surprisingly long, complex songs (e.g., the Superb
Lyrebird). Sometimes birds generate sounds by using substrates
(like woodpeckers) or their wings (like Ruffed Grouse) or
special feathers (like American Woodcock) or special wings (like
manakins). Neat video of a Red-capped Manakin (Pipra mentalis)
using its wings to generate sound. Male Anna's Hummingbirds use
their tail feathers to generate sound. Most sounds, however, are
produced by the avian vocal organ, the syrinx. House Wren
singing Common Loon calling The syrinx is located at the point
where the trachea branches into the two primary bronchi.
According to one model of syrinx function, sound is generated
when: Click on the sonagram to hear a 'self-duet' by a Clay-
colored Robin (Source: Doug Von Gausig's webpage a