Chimpanzees 'struggle' with straws
Some humans struggle with chopsticks, but learning the correct way to use a straw is equally challenging for a chimp.
For both species there is one good way to master such a tricky skill - watch how someone else does it.
Scientists used straws to demonstrate experimentally for the first time that chimpanzees improve their use of tools by learning from others.
Instead of relying on trial and error to discover that you can suck through a straw, they made the connection immediately after being shown the technique.
To a chimp, a straw looks like a stick, which would normally be used to dip into a food source. Wild chimpanzees in Africa have been observed using sticks to fish for termites and scoop honey from hives.
In the experiment, chimps were given juice boxes with a small hole and straws to drink with.
One group of five animals used the straws like dip sticks, pushing them through the hole to collect juice. Another was taught the more efficient way to use a straw - by sucking through it.
When apes from the first group watched either another chimp or human demonstrate straw sucking, all switched to the better technique.
The Japanese and British scientists, led by Dr Shinya Yamamoto, from Kyoto University, wrote in the online journal Public Library of Science ONE: "When chimpanzees are dissatisfied with their own technique, chimpanzees may socially learn an improved technique upon close observation of a proficient demonstrator.
"This study provides important insights into the cognitive basis for cumulative culture in chimpanzees, and also suggests possible conditions in which cumulative cultural evolution could arise even in non-human animals."