Quirks and Quarks

Females flinch from the mating call of the world's loudest bird

In a case of sexual selection gone wild, the white bellbird of the Amazon has the loudest bird call ever recorded

The white bellbird of the Amazon has the loudest bird call ever recorded

The call of the male white bellbird peaks at 125 decibels (Anselmo d'Affonseca/Instituto Nacional de Pesquisas sa Amazonia, Brazil)

The loudest bird in the world has a song that rivals a pneumatic drill, a rock concert or a jet engine. And when the male white bellbird approaches a female, she's subjected to the full volume of his performance. 

The pigeon-sized white bellbird lives in the remote mountains of the northern Amazon, which means there are few humans around to be driven mad by its mating cry. Using sound level meters normally used for industrial noise monitoring researcher have now managed to measure what they claim is the loudest bird call ever documented.

Just how loud?

Jeff Podos, a biologist the the University of Massachusetts Amherst, collaborated with colleagues at the Instituto Nacional de Pesquisas de Amazonia in Brazil to capture the bellbird's call.  Their measurements revealed that the bellbird's song reaches average decibel levels of 117, and peaks at 125.

Podos determined the white bellbird generates three times the sound pressure of the previous record holder, another Amazonian bird called the screaming piha.

In fact the calls can sometimes be heard together.  On hearing the white bellbird's siren, the screaming piha will often be inspired to emit its own call, which in only nine decibels quieter.   

Sexual selection gone wild

The male bellbird sings his loudest songs only in the presence of females. According to Podos, this is quite a performance to witness. The male bobs and weaves and finally turns to face the female as he makes the loudest part of his two-toned call.  On seeing this, the female will often quickly move away so as to avoid taking the full brunt of the call.

Podos says he assumes the female appreciates the sound and may be judging the quality of the call as a way of sizing up the male's potential as a mate. He does wonder, however, how the female is able to tolerate such volume at close range on a nearby perch.

The female bellbird is the recipient of the loudest call (Anselmo d'Affonseca/Instituto Nacional de Pesquisas da Amazonia, Brazil)

The Wall of Sound

To understand how the bellbird produces such a call, Podos and his colleagues, have been investigating its anatomy. 

They found its chest to be five times thicker than most birds the same size, due to muscular development that may help produce the call.  In addition the shape of the beak in the open position is similar to the flared end of a trumpet, which is designed to help amplify the sound. 

The screaming piha was the previous loudest bird recorded