Thanks to James Gorman for the latest examination of animal intelligence:
Chalk up another achievement for parrots, with an odd twist that raises questions about whether the experimenters or the birds know best.
Anastasia Krasheninnikova and colleagues at the Max Planck Institute for Ornithology in Germany tested four species of parrots in an experiment that required trading tokens for food and recently reported their findings in the journal Scientific Reports.
Would the birds resist an immediate reward to trade for something better? Many species have shown the ability to hold off on an immediate treat — like a dry corn kernel — for something tastier later on, like a bit of walnut.
Chimpanzees, monkeys and cockatoos, among other species, can defer gratification. But using tokens for trading had not been tried before in birds, Dr. Krasheninnikova said.
Here’s how it worked. First the birds, great green macaws, blue-throated macaws, blue-headed macaws and African grey parrots, learned that they could barter tokens for foods of different value — to the birds, that is.
A metal hoop could be traded for a piece of dry corn, the lowest value food, a metal bracket for a medium value sunflower seed and a plastic ring for the highest value food, a piece of shelled walnut.
The birds were then offered various choices, like a piece of corn or the ring. They all reliably chose to forgo the corn and take the ring. Then they were able to trade the ring for a piece of walnut.
Read the whole story here.