BBC News notes that the cleverest crows, New Caledonian crows (Corvus moneduloides), opt for two tools when they try to pry out food:
The crows were presented with:
- A scrap of meat, which was tucked away, out of reach, in a box;
- A small twig, which was too short to reach the food;
- And another longer twig, which was long enough to reach the food, but was locked away well out of bill-grabbing range in another box.
The birds surprised the scientists with their quick thinking.
Alex Taylor, lead author of the paper, said: “The creative thing the crows did was to use the short stick to get the long tool out of the box so that they could then use the long stick to get the meat.”
Russell Gray, another author of the paper, told the BBC News website: “What is most amazing is that most of them did this on the first trial.
“The first time we gave them the problem, six out of seven tried to do the right thing.
“They took the little tool and they tried to get the big tool out, which we had made quite hard to reach, and four out of the six managed to get the big tool out and then use this to get to the food.”
In another experiment, the positions of the long and short twigs were reversed.
The team found that all apart from one crow briefly attempted to use the long twig to try to retrieve the short twig from box before quickly correcting their mistake and using the long twig to directly access the food.
The scientists said the crows’ performance was comparable to that of the great apes in similar experiments.
The team believes that because the birds were able to solve the problem on their first attempt they were using analogical reasoning rather than trial and error.
The original article includes a short video of a clever crow in action.
I’ve written before about clever crows. Although they’re good at analogies, they’re terrible at antonyms.