The Amazon rainforest is a deafeningly noisy place, a constant cacophony of jungle animals trying to make themselves heard. Amid the din, the male white bellbird has evolved a winning strategy—he may be the loudest bird on Earth.
This ivory-white bird will perch at the top of a dead tree, high in the montane forests of northern Brazil, and gape open his mouth to issue a grating, hair-raising screech.
“They just seem alien,” says Jeff Podos, a biologist at the University of Massachusetts at Amherst and co-author of a paper released today in the journal Current Biology. According to the study, the bird’s call is twice as loud as its cousin, the screaming piha, another Amazon native.
The bellbird’s call is at least nine decibels (dB) louder than that of the piha, reaching volumes of 125 dB—that’s similar to what you’d hear standing next to speakers at a rock concert. By comparison, a normal human voice is about 60 dB.
What really surprised scientists is the males will blast their notes directly into a curious female’s face, says Russ Charif, senior bioacoustician at the Cornell Lab of Ornithology, who wasn’t involved in the study.
Charif believes that the males may have evolved this trait to impress females, as the louder birds are presumably more fit. It’s likely “females use the loudness to assess the males, presumably preferring louder males,” he says by email. (Read why birds matter, and are worth protecting.)
“This is a cool study, appears to have been carefully done, and the results seem solid,” Charif adds, noting how tricky it is to record animals’ sounds in the wild. The research also offers more insight into the study of sexual selection, and how animals will go to incredible lengths to secure a mate.
Turning up the volume
Podos and colleagues didn’t set out to find the world’s loudest bird. Co-author Mario Cohn-Haft, curator of birds at the Instituto Nacional de Pesquisas da Amazônia in Manaus, Brazil, brought a specimen of a male white bellbird back for the museum after a research trip.
Back in his office, Cohn-Haft examined the animal and found its ribs were embedded in thick, well-defined abdominal muscle—prompting him to hypothesize the unusual structure had something to do with their high-volume calls.
Discovering that no one had published a study about bellbirds or their singing, the team set out into the rainforest to record the male bird’s sounds. (Females, which sport greenish yellow plumage, don’t vocalize at all.)
The team tracked and recorded wild pihas and bellbirds and classified their calls into three types. Those are the male pihas' call, the male bellbirds' Type 1 song—which is quieter and longer—and the male bellbirds' Type 2 song, which is louder and shorter. (Read about some of the world’s loudest animals.)
The authors then calculated the calls to see how loud each would be one meter away from the bird.
The pihas calls proved to be the softest, and the Type 2 bellbird calls the loudest. But the researchers weren’t able to say whether the distinct musculature is part of the bellbird’s singing talent.
There's a reason the Type 2 song is so simple and short—reaching such a high decibel requires some effort.
“If you asked a trumpeter to make the loudest sound they could,” Podos says, it would “make a sound like the bellbird—one pure crystal note.”
'Adorably dorky'
Bellbirds have a very precise courtship ritual, which always ends with the male pivoting on the branch and blaring one last note at the female. The sound is likely loud enough to damage the female’s hearing, but the scientists found no evidence of such an impact.
"She’s played this game before, so she knows what’s coming,” Podos says. For instance, when he puffs up in preparation to make that big call at her, the female often "flies off to a more reasonable distance." (Read about “moonwalking” birds and other avian courtship rituals.)
However, the team didn’t witness any successful copulations among the observed birds.
Bob Mulvihill, an ornithologist at the National Aviary in Pittsburgh, says that male birds generally will tone down courtship displays if the female seems fearful. For this reason he suspects the male bellbirds’ high-call volume teeters at the extreme edge of successful sexually selected traits.
Adds Mulvihill, it’s hard not to giggle at the idea of male wanting to woo a female so badly he blasts her right off the perch.
That is, Podos says, "adorably dorky."
You May Also Like
Go Further
Animals
- Octopuses have a lot of secrets. Can you guess 8 of them?
- Animals
- Feature
Octopuses have a lot of secrets. Can you guess 8 of them? - This biologist and her rescue dog help protect bears in the AndesThis biologist and her rescue dog help protect bears in the Andes
- An octopus invited this writer into her tank—and her secret worldAn octopus invited this writer into her tank—and her secret world
- Peace-loving bonobos are more aggressive than we thoughtPeace-loving bonobos are more aggressive than we thought
Environment
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
- Food systems: supporting the triangle of food security, Video Story
- Paid Content
Food systems: supporting the triangle of food security - Will we ever solve the mystery of the Mima mounds?Will we ever solve the mystery of the Mima mounds?
History & Culture
- Strange clues in a Maya temple reveal a fiery political dramaStrange clues in a Maya temple reveal a fiery political drama
- How technology is revealing secrets in these ancient scrollsHow technology is revealing secrets in these ancient scrolls
- Pilgrimages aren’t just spiritual anymore. They’re a workout.Pilgrimages aren’t just spiritual anymore. They’re a workout.
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- This ancient cure was just revived in a lab. Does it work?This ancient cure was just revived in a lab. Does it work?
Science
- The unexpected health benefits of Ozempic and MounjaroThe unexpected health benefits of Ozempic and Mounjaro
- Do you have an inner monologue? Here’s what it reveals about you.Do you have an inner monologue? Here’s what it reveals about you.
- Jupiter’s volcanic moon Io has been erupting for billions of yearsJupiter’s volcanic moon Io has been erupting for billions of years
- This 80-foot-long sea monster was the killer whale of its timeThis 80-foot-long sea monster was the killer whale of its time
Travel
- How to plan an epic summer trip to a national parkHow to plan an epic summer trip to a national park
- This town is the Alps' first European Capital of CultureThis town is the Alps' first European Capital of Culture
- This royal city lies in the shadow of Kuala LumpurThis royal city lies in the shadow of Kuala Lumpur
- This author tells the story of crypto-trading Mongolian nomadsThis author tells the story of crypto-trading Mongolian nomads