LONDON — Gibbons are jungle divas. The small apes use the same technique to project their songs through the forests of southeast Asia as top sopranos singing at the New York Metropolitan Opera or La Scala in Milan. That was the conclusion of research by Japanese scientists who tested the effect of helium gas on gibbon calls to see how their singing changed when their voices sounded abnormally high-pitched. Just like professional singers, the experiment found the animals were able to amplify the higher sounds by adjusting the shape of their vocal tract, including the mouth and tongue. It is a skill only mastered by a few humans, yet gibbons are able to do it with minimal effort, according to Takeshi Nishimura from the Primate Research Institute at Kyoto University. Singing is particularly important to gibbons, which use loud calls and songs to communicate across the dense jungle. Their exchanges, described by primatologists as “duets”, can carry as far as two kilometers. “Our data indicate that acoustic and physiological mechanisms used in gibbon singing are analogous to human soprano singing, a professional operatic technique,” Nishimura and colleagues wrote in a study in the American Journal of Physical Anthropology on Thursday. — Reuters