Remarkable video clips of wild chimpanzees using "tool kits" to dig out termites from their underground nest have been recorded by scientists who believe it is the most sophisticated culture yet observed in great apes other than man.
Although chimps are known to use long twigs as simple tools to fish for termites - a nutritious delicacy - this is the first time that a far more complex behaviour involving two different kinds of tools has been observed in the wild.
Crickette Sanz of the Max Planck Institute in Leipzig and David Morgan of Cambridge University make the video with the help of hidden cameras trained on termite mounds in the tropical forests of the Congo that chimps were known to frequent.
They filmed the chimps using a thick stick, which they had previously prepared by stripping it of its leaves, to push a long tunnel about a foot deep into the heart of the underground termite nest.
Once they had removed the stick, they pushed a far more delicate twig that had been deliberately frayed at one end down the tunnel and into the heart of the nest, said Professor Andrew Whiten of Edinburgh University.
"These chimpanzees use something that doesn't happen anywhere else.
They use a tool kit.
They left one part of the tool kit, which is a big strong stick, at the termite nest, " he told the American Association for the Advancement of Science in St Louis.
"They'll pick it up and push it right down into the ground.
What they are doing is inserting it to make a tunnel into the termite's subterranean nest.
"They use their hands and their foot to dig down, so they look like Mr Macgregor with his spade digging down with great effort.
We don't understand how possibly they could have worked out how to do that." he said.
The next stage involves pulling the stick out, discarding it and using another flimsier twig with a frayed end which they push down the tunnel to fish for termites that crawl onto the twig which is then used as a feeding utensil.
Professor Whiten said that the remarkable tool-using behaviour of the chimps was passed on between members of the same troop as a cultural tradition unique to that group of animals.
He said it is one of more than 40 different behaviours scientist have observed in wild chimps that are culturally inherited by young animals who have watched older members of the same group perform the same task.
Research has shown that such behaviour varies across Africa with chimps in the west displaying significantly different cultural traditions to chimps in the east.
"Those difference in behaviour have all the hallmarks of being traditions.
We've discovered that there are many of them and they are really rich in variety," he told the meeting.
"In far west Africa, chimps use stones and branches to crack nuts.
That's really important to them.
But chimps don't do that in East Africa.
And even more important, in west Africa they don't do it on the east side of a major river.
"That tradition has not crossed the river.
That's just one of over 40 examples of behaviour patterns that do not appear to have any genetic or environmental explanation," Professor Whiten said.
Some culturally acquired behaviour may have been passed down the generations for centuries because it was important for survival, but other cultural traditions appear to be nothing more than ephemeral trends.
"Jane Goodall many years ago described one young female chimp going around shaking her hands, like the kind of thing teenagers would do, and her young female friends started to do the same thing, like it was the cool thing to do.
Then it faded out," Professor Whiten said.
Other primatologists have found that culture also appears to be common in the other species of great apes - the gorilla and the orang utan.
Tara Stoinski of the Atlanta Zoo has made a study of culturally acquired behaviour in different groups of captive gorillas.
"We identified 40 behaviours that varied," she told the American Association.
One group of gorillas in her own zoo for instance had learnt to use sticks to move the electrified wires that were designed to keep them from stripping the bark of a nearby tree.
"The gorillas will go and collect sticks, which don't transmit electricity, to move the wires around, so allowing them to get into areas where they are not supposed to be going,? Dr Stoinski said.
"In some groups a particular behaviour would be present and everyone in the group would do it.
And yet when you go to another group, not a single animal would show this behaviour.
"What we found with gorillas in zoos is that the majority of what we considered to be cultural behaviours are gestures.
This makes sense when you think that gorillas in captivity don't have to work nearly as hard to survive as wild animals.
They have more time to engage in social behaviour," she said.
"We also found considerable differences not only between zoos but even within a zoo.
In my zoo we have four groups of gorillas and four different kinds of behaviours," Dr Stoinski said.
However, the primatologists warned that the study of primate culture is getting more difficult because all species of great ape are threatened with extinction.
"On a daily basis we're losing the opportunity to document culture in wild gorillas because these populations are disappearing faster than we can actually study them," she said.