From our native singers to the exotic species of the tropics: It is well known that some birds make surprisingly loud sounds to impress their fellow birds. But which one holds the record? The loudest known courtship calls can be heard from the Amazon-native Einlappenkotinga (Procnias albus). The males scream at their females from close range with up to 125 decibels, scientists have found.
Some are gorgeous like the peacock, some dance and others are known to draw attention to themselves acoustically: the males of many bird species have developed some amazing strategies to win over females. With some species, the ladies apparently find it sexy when the candidates can utter particularly powerful tones. The single-flap kotinga apparently wants to convince particularly through volume, according to researchers working with Jeff Podos from the University of Massachusetts in Amherst.
Screamers with sex appeal
They observed the bizarre birds in the Brazilian rainforest and recorded their sounds with microphones. As it turned out, the males do not turn up particularly in order to make themselves noticeable from afar, but rather when a female is very close: from a distance of sometimes only four meters they blare their metallic-looking calls to the female birds with a peak of 125 decibels on the ears. “They also turn to direct the last tone of the call specifically at the females,” says Podos.
“It seems surprising that the females voluntarily stay so close to the singers at this volume. Maybe they want to assess the males up close, even if doing so could even run the risk of damaging their hearing systems, ”says Podos. Apparently there is at least one mitigating effect on the extent of the noise: the louder the males call, the shorter their performance, the researchers found.
According to them, this seems to reflect how extremely strenuous the generation of sound is for the birds, which weigh only about 250 grams. The scientists now want to continue researching which physical and anatomical structures and behaviors enable single-flap kotingas to generate such loud sounds and to endure them without hearing damage.
Video: Anselmo d’Affonseca
Source: Cell Press, technical article: Current Biology, doi: 10.1016 / j.cub.2019.09.028