The evidence is mounting that culture isn't something unique to us humans: Orangutans in Borneo have developed and passed along a way to make a useful, improvised instrument, researchers report.
When in a tight situation, the orangutans will strip the leaves off a twig and make a crude musical instrument to alter the calls they use to ward off predators — not exactly a Stradivarius, but it seems to get the job done.
Several animals, particularly our primate cousins, have been found to use tools to aid in efforts such as foraging for food, a sign of culture, specifically the transmission of knowledge. This new finding marks the first time an animal has been known to use a tool to help it communicate, say the scientists who studied the behavior.
Wild Bornean orangutans (Pongo pygmaeus wurmbii) emit a particular call known as a kiss squeak — a sharp intake of air through pursed lips that makes a kissing sound.
Orangutans make this noise when they feel threatened, for example, when they fear a predator — such as a snake, clouded leopard, tiger or human — most likely to ward the predator off and not as a distress call. (Orangutans are somewhat solitary and it would take too long for the next nearest orangutan to respond.)
Kiss squeaks come in three different forms: unaided (lips only); with the hand in front of the lips; and with leaves in front of the lips. The leaves are stripped off a twig and held in a bundle in front of the orangutan's mouth while the animal makes the kiss squeak.
When scientists first observed this behavior, they weren't sure exactly why the orangutans used the leaves. The new study suggests that the tool lowers the frequency of the kiss squeak, making the orangutan producing the call sound bigger to their potential predator.
Full story here.