Crockford

This, Crockford said, is the most fascinating question.

Then they have a bunch of specific calls they give when interacting with others to keep the interaction going longer, such as laughing during play, or teeth clacking during grooming,” Crockford said.

“It seems they can combine two meanings together into an utterance, for example, 'rest' and 'food', which may translate into something like 'I'm staying longer at this food patch'. Telling others what you are doing, helps others decide if they want to stay and do it with you or move on. Such utterances probably mainly help bond partners to coordinate their activities in the dense forest vegetation so that they can stay together for longer,” Crockford added.

“We now realize,” Crockford said about the chimpanzees, “that to understand the complexity of animal 'languages', we need to study the animals' natural communication — what they communicate to each other. In the wild, chimps for example use specific calls for a number of contexts they never experience in captivity — they have a specific bark to recruit others to hunt, and other calls for territorial defense.”

“We're just beginning to understand the complexity of chimp communication — as they have become critically endangered. As they are hunted by humans for the pet trade and for meat, and their forests are destroyed, their communities are broken up, risking that they lose their local cultures,” Crockford said.