Anyone who has been woken at dawn by a chorus of songbirds knows that birds can be surprisingly loud for their size. But according to new research highlighted this week, two species take avian volume to an extreme rarely matched anywhere in the animal kingdom: scientists say their calls rival the racket of a jackhammer tearing up pavement.
A jackhammer at close range sits in the range where human hearing starts to hurt â loud enough that construction crews wear ear protection to avoid permanent damage. That a creature weighing a fraction of a bag of sugar can generate a comparable blast of sound is what makes the finding so striking.
Why birds shout
Extreme loudness in birds is almost always about one thing: reproduction. In dense tropical forests, sound doesn’t travel well. Leaves, trunks and humid air absorb and scatter calls, meaning a male trying to advertise himself to a potential mate may be competing against a wall of background noise from insects, frogs, wind and rain.
The solution many species have landed on is raw power. A male that can out-shout his rivals can broadcast his presence across a wider area, reaching more females and warning off competitors without the risk of a physical fight. Volume may also act as an honest signal of fitness: producing a deafening call takes muscle, air and energy, and a weak or unhealthy bird simply can’t fake it.
The anatomy of a scream
Birds don’t have vocal cords like humans do. Instead they use a specialised organ called the syrinx, located where the windpipe splits toward the lungs. Membranes in the syrinx vibrate as air passes over them, and birds can control those vibrations with remarkable precision â which is how a single bird can produce two notes at once.
In the loudest species, that machinery appears to be paired with unusually thick muscles and specialised anatomy around the throat and chest, essentially turning the bird into a living amplifier. Some ultra-loud species also have physical adaptations that seem to help them tolerate their own noise, since a call powerful enough to damage hearing is being produced only centimetres from the bird’s own ears.
There are trade-offs. Birds that sing at extraordinary volume often do so in short bursts rather than long, complex songs, and researchers have noted that as loudness goes up, the length of the call tends to go down. There is only so much air and energy to spend.
Measuring the loudest
Recording these records is harder than it sounds. Sound pressure falls off sharply with distance, so a measurement taken from a few metres away means little unless the distance is carefully documented and the reading standardised. Researchers typically need to get close with calibrated microphones â no small feat when the subject is perched high in the canopy of a remote forest and likely to flee.
That difficulty means the list of “loudest birds” has shifted over the years as better equipment and more fieldwork have filled in gaps. It is entirely possible that species in poorly studied habitats are louder still, simply because nobody has managed to point a microphone at them yet.
Beyond the trivia value, the work feeds into a broader scientific interest in how animals communicate in noisy environments â a question with growing urgency as human noise from roads, shipping and cities increasingly drowns out the natural soundscape. Read More
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