A Bornean orangutan uses leaves stripped from a twig to alter the frequency of its kiss squeak call, which it makes when it feels threatened.

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.

Click here for photos and more on this story from Livescience.com.