University of Massachusetts Amherst biologists have identified the bare-throated bellbird and the red-legged seriema as new contenders for the world’s loudest bird, with calls surpassing 120 peak decibels. Published in the journal Evolution, the findings reveal physiological traits behind avian volume.
Biologists at the University of Massachusetts Amherst have expanded the record books for avian volume, identifying two new bird species that rival the sound of heavy industrial machinery. The findings, published in the journal Evolution, detail how researchers measured the acoustic output of birds in the wild.
How Researchers Measured 123 Bird Species in the Field
Menezes, the research team set out to understand why certain birds produce such powerful vocalizations. Past scientific efforts relied on capturing animals and running controlled tests in a laboratory. Podos and Menezes rejected that approach as impractical for international comparisons of large bird populations.
Measuring volume, or amplitude, presents a fundamental physics hurdle because sound diminishes over distance. A call that deafens someone close up may fade completely a few hundred yards away. To solve this, the researchers adopted equipment from two distinct industries: portable sound meters built for workplace safety monitoring, and laser rangefinders invented by golfers to measure exact distances on a course. Armed with these portable tools, the duo cataloged the amplitude of 123 bird species across Massachusetts and Brazil, gathering volume data for 113 of those species for the very first time.
Bare-Throated Bellbirds and Red-Legged Seriemas Break 120 Decibels
The survey revealed an enormous 58-decibel range across avian calls. Hummingbirds registered around 64 decibels, comparable to the volume of an ordinary human conversation. At the opposite end of the spectrum, the bare-throated bellbird and the red-legged seriema both pushed past 120 peak decibels.
That volume surpasses the noise of standing next to a revving chainsaw or a pneumatic jackhammer. The new claimants join an elite tier of acoustic powerhouses. In 2019, Podos clocked the Amazon’s white bellbird at 125 decibels, a feat that earned a certified entry in Guinness World Records. While researchers noted that determining an absolute winner depends on whether one measures individual peak squawks or species averages, they emphasized that the race for a crown misses the point.
Physical examinations of the record-breaking species showed consistent anatomical traits. The loudest birds feature larger bodies with bulky muscles capable of greater air compression, alongside wide beak openings that function similarly to the flared bell of a brass trumpet to project sound.
The Unresolved Evolutionary Mystery Behind Avian Volume
Despite uncovering the physical mechanics behind extreme volume, the data challenged the researchers’ initial ecological hypotheses. Podos and Menezes had theorized that the loudest birds would share three specific traits: they would be weak flyers relying on sound to make up for limited mobility, they would live in dense forests where foliage blocks vision, and they would practice polygamy to attract multiple mates across wide areas.
The red-legged seriema directly contradicted those assumptions. The researchers noted that the seriema thrives in open habitats like pastures and maintains strict monogamy during the breeding season, forming a dedicated pair bond.
For now, the evolutionary driving forces behind why these animals invest such high amounts of energy into screaming remain unknown, prompting the research team to plan further expeditions into the field.