Rufous-bellied Thrush: bird song and cymatics · Kyma Birds

On lek nights the male inflates air sacs in his chest and gives deep, resonant booms (around 100 Hz) in rhythmic series every couple of seconds for hours, audible kilometers away. The booms are interspersed with metallic “ching” calls.

A slow, steady series of identical, low, hollow “hoo” notes, likened to a distant dog bark or a soft moo: about one a second near 0.6 kHz, with a faint second harmonic. A bird can keep it up for minutes while the pitch creeps upward.

Clear, haunting, flute-like whistles that jump between pitches like a played melody. Phrases of 4–8 pure tonal notes fall between about 1 and 2.5 kHz and come every 5–7 s, with soft churring notes mixed in.

The male’s territorial yodel: a rising wail that breaks into repeated, undulating tonal phrases. It is low, pure and echoing, and carries for kilometers over still lakes.

The sound of the Amazon: an explosive, whip-like “pi-pi-YO” (qui-qui-yo) of sharply up-slurred whistles that sweep from about 1.5 to 5 kHz. Several lekking males answer each other, so a song comes every few seconds. It is over 110 dB at 1 m.

Loud, rich and melodious phrases of clear fluty whistles, swoops and quick flourishes. Long prized as one of Asia’s finest songsters.

Ringing, bell-like tolls and liquid notes mixed with clicks, cackles, creaks and wheezes, in phrases repeated every few seconds.

Rich whistled phrases repeated over and over, each repetition louder and faster, building to a ringing climax and then starting again. Often sung as a duet and at dawn.

Unhurried, rich caroling: liquid, slurred phrases of 4–10 notes, mostly 1.8–2.7 kHz, repeated every few seconds with each phrase a little different. The classic sabiá dawn song.

Loud virtuoso song in short, varied phrases: slow swelling “piu piu piu” crescendo whistles, explosive rapid trills, rattles and gurgles, separated by dramatic pauses.

A loud, restless medley of whistles, rising slurs, buzzy rattles, chatters and trills, many borrowed from other species. Phrases change every second or two across 2–5 kHz, with buzzy broadband passages reaching higher.

A leisurely, ringing, lilting series of well-spaced phrases of pure, liquid, flute-like notes, sometimes with thin squeaky or gurgling ones, mostly between 2.5 and 5.5 kHz with pauses between.