Raccoons managed to solve an ancient Greek puzzle
But there are questions over how much they understood.
An ancient Greek fable has been used to test raccoon intelligence – and while the mammals under-performed in some regards, scientists were still very impressed.
The Crow and the Pitcher, written by Aesop, is about a thirsty crow who realises that to get a drink it needs to drop stones into a pitcher, raising the water level.
The experiment has previously been used on birds and small children to test their understanding of cause and effect, but this was the first time it was used to see if mammalian carnivores could grasp the principles of water displacement.
Following the model laid out in previous studies, the raccoons were then trained to drop stones into the tubes.
By balancing stones on the tube’s rim the raccoons accidentally knocked the stone in, raising the water level and granting access to the marshmallow – helping provide a link in the animals’ minds between the stone dropping and the treat.
Seven raccoons interacted with the stones during training, with four collecting the reward and a further two of those learning to pick the stones up and drop them into the water to get the reward.
A third decided to just overturn the heavy tube to get to the marshmallow.
But to determine whether there was any actual understanding behind the successful raccoons’ decision, things were about to get a lot harder.
Unlike birds and humans, the raccoons didn’t always choose the most functional option. But Stanton doesn’t think that reflects badly on the animals.
“We found raccoons to be innovative in many aspects of this task, and we observed diverse, investigative behaviours that are unique to raccoons,” she said, talking up the raccoons’ exploratory behaviour.
Stanton was also keen to stress that the raccoons had less time with the stones than birds did in previous studies, while the build of their paws may also have had an effect.
“Our study demonstrates that captive raccoons are able to learn to solve novel problems and that they approach classic tests of animal cognition in diverse and exciting ways. We can’t wait to see what they do next,” said the University of Wyoming’s Sarah Benson-Amram.
