Scientists record world's loudest bird song
Male attracts mates by screaming in their face
published : 23 Oct 2019 at 12:44
writer: Associated Press/TNS
WASHINGTON: Researchers say they have recorded the loudest bird call in the world, and the tiny birds use their booming voices to attract potential partners.
The white bellbird, living high up in the trees of the Brazilian Amazon's misty, cloud forests, have two distinctive types of songs, one of which can reach 125 decibels, according to a paper published Monday in the peer-reviewed journal Current Biology.
The songs, although less complex than some other birds, have a sound pressure three times greater than that of the previous record-holder, the screaming piha.
Standing beside a siren clocks in at 120 decibels, and repeated or routine exposure to sounds that loud can cause pain and ear injury, according to the Centers for Disease Control and Prevention.
Study author Jeffrey Podos said the birds must have developed such loud calls to attract mates, although he never actually saw the flirting tactic work.
"All we saw were females turn down their prospective suitors," Podos said. "Most animal courtship 99 out of 100 times it doesn't lead to anything."
When males are alone they primarily sing a quieter, one note song. But when a female is in the area, a male will turn his back to her and start signing the louder and more rare two note song as she approaches.
"When the female's right next to him, the male sings only his very loudest song," Podos said. "The first note he sings away then he pivots, swivels around and he's got his beak wide open and he blasts that second note it's like Broadway." (continues)
But Podos said by the time the male swings around, the female has usually already flown away because "she knows what's coming." He said the males aren't trying to startle potential mates, but the loudest notes might be overly aggressive.
"She might still be interested in the male, maybe in spite of the song," Podos said. "She just has to endure this crazy habit of the male."
Podos thinks that birds are able to sing so loud because of their wide beaks, which they use to swallow fruit whole. Study co-author Mario Cohn-Haft first noticed during a dissection that the birds also have thick abdominal muscles that make it look "like its been doing ab crunches," which may be related to their loud voice, Podos said.
Ornithologists have speculated in the past that white bellbirds may be the loudest birds in the world, but no one has measured their calls until now, Podos said. Traditionally it's been difficult for researchers to measure animal sounds in a standardized way, so Podos and his colleagues used new-generation recorders and a laser rangefinder similar to the kind golfers use to determine how far away the animals were.
"We knew they would be really loud, but they were a little bit louder than I think we thought they would be," Podos said. "It's just super cool to be there and listening to them. The sound it just resonates, it carries all day. It's like this musical soundtrack to the forest."
Podos said he hopes to study the three other species of bellbirds and better understand what the birds do to help them be successful in mating. He worried that the fires being set in the Amazon may threaten the birds' mountain habitat and hopes that their research will encourage locals to help prevent further damage.
"We want to work but we feel like we have to do it quickly before the place gets damaged," Podos said.