orangutan ruse misleads predators 猩猩妙计吓天敌-凯发k8官网

wild orangutans in borneo hold leaves to their mouths to make their voices sound deeper than they actually are, a new study shows.

一项新研究显示，波罗洲的野生星星将树叶贴近嘴边使它们的声音听起来比平常低沉。

the leaf trick gives an exaggerated impression of the ape's body size

the apes employ the leaf trick when they are threatened by ¹（食肉动物）, according to scientists observing them.

by holding leaves to their mouths, the orangutans（猩猩） lower the frequency of the sounds they produce.

this is used to ² off predators, giving them the impression the apes are a bigger target.

the international team made the discovery while observing ³ calls made by the orangutans.

the apes make the sounds in response to approaches by snakes, clouded ⁴, tigers or humans.

these distress calls are known as "kiss ⁵" because they involve a sharp ⁶（引入口，通风口） of breath through pursed（皱起，使缩拢） lips, producing a sound similar to that made during a kiss.

but by using the leaves to modify the sound that comes out, orangutans deceive predators into thinking the calls are being made by a bigger animal.

co-author madeleine hardus, from the university of utrecht in the netherlands, told bbc news: "this study clearly indicates that the abilities of great ape communication have been traditionally undervalued（低估，看轻） and that there may be traces of language ⁷（先驱者，前导） in our closest relatives, the great apes."

she added that the findings suggest that ⁸ calling behaviour is not ⁹ based on instinct（本能）, but instead is socially learned.