Chimp urinating is ‘scientifically interesting’

Scientists from Germany’s Max Planck Institute presented the primates with a tube partially filled with water, with a floating peanut inside.

The peanut was too near the bottom of the glass tube for the chimpanzees to access. The only way to get the food was to transfer water from a nearby dispenser into the tube.

Some of the chimps made several trips to the dispenser and eventually retrieved the peanut by spitting more water into the tube so the food floated to the top.

The move echoed Aesop’s fable where a crow used stones to raise the water level so it could have a drink.

One of the chimps in this latest experiment even urinated into the tube to raise the water level.

The lead scientist, Daniel Hanus from the Max Planck Institute for Evolutionary Anthropology in Germany, told Channel 4 News his team were “really surprised to see that kind of innovative behaviour in chimps”.

He added: “Interestingly, the individuals that solved the problem were not just spitting randomly. Instead their behaviour seemed very goal directed and could not be explained by trial-and-error approach.

“In addition, instead of spitting, one young male chimpanzee once urinated into the tube in order to raise to water level and bring the nut into reach.

“Obviously, he understood that liquid is needed to solve the problem – regardless where it’s coming from. That was not only funny but scientifically interesting since it can be seen as a manifestation of cognitive transfer.”

The full study has been published in the Plos One journal.