The chimpanzees found in Comoé National Park in Côte d’Ivoire have been filmed cleverly fashioning sticks to dip into tree holes to soak up water.
Researchers from Comoe Chimpanzee Conservation Project set up cameras in the African park to film chimpanzee activity. They discovered, to their surprise, that chimps of all ages were chewing on sticks to loosen their fibres and then using them to dip for water in deep holes.
According to a report in the American Journal of Primatology, this is the first time that this kind of water-dipping behaviour has been found to be widespread in chimpanzee populations.
Chimpanzees have been previously observed using stick tools to probe for termites and honey, but dipping for water has only been sporadically observed.
When researchers examined the sticks the chimps used to dip for water, they found that the length, diameter and brush length were different to the sticks used for termites and honey from bees’ nests. The chimps were observed chewing the ends of the sticks to turn them into soft, absorbent ‘brushes’, and these water-dipping sticks were found to have longer and thicker brush tips compared with other sticks.
The scientists also noted that this behaviour was widespread throughout different chimp age groups, sex classes and communities. This led them to conclude that this is clear evidence of wild chimpanzees developing a new culture, which is a very exciting discovery for them.