100 YEARS OLD AND STILL CHATTING UP BIRDS...
TALKING of birds, as I seem to recall I was doing when we last met on Friday, the latest issue of Animal Behaviour journal tells of an experiment with crows even more intriguing than the parrot-related findings I mentioned last time.
The paper is entitled Ravens Remember The Nature Of A Single Reciprocal Interaction Sequence Over Two Days And Even After A Month and report an experiment showing that ravens are even more canny than we had previously thought. Since earlier experiments have shown phenomenal problem-solving abilities in these birds, the new findings lift my view of their astuteness to unprecedented heights.
The question they investigated is basically whether ravens hold grudges. Specifically, if an experimenter behaves unfairly towards a raven, will that raven remember and avoid the same experimenter in the future?
The experiment involved training the ravens to exchange bread (a food described as “low-quality”) for cheese (“high-quality”). Specifically, the experimenter showed the raven an open palm of one hand while holding a piece of cheese between the fingers of the other hand. The raven had previously been trained to swap tokens to food, so it quickly learnt to exchange bread for a piece of cheese.
This was a bit risky for the raven as it had to invest the bread before it received the cheese but after thinking it over most of the ravens decided to give the experimenter their bread and wait for the cheese.
Some of the experimenters however took the bread then ate the cheese themselves. The question was whether the ravens would remember which of the experimenters could be trusted and which couldn’t.
To find out, they repeated the experiments after a break of either two days or a month. After that time had elapsed, they gave the ravens a choice of which experimenters to deal with. Would they go for the ones that had been fair the first time round or be just as likely to deal with the unfair?
To find out more of what was going on in the birds’ minds, they also let some birds watch other birds’ trials to see if they drew conclusions about the experimenters from observation without direct participation.
The results showed that ravens show reluctance to deal with experimenters who have been unfair to them in the past, even if that was a month ago but seeing an experimenter being unfair to another crow did not seem to affect their own dealings.
Wishing to hear a raven’s own view of this, I had a chat with one of the experimental birds who was very clear what he thought. “Well of course I’m not going to hand over bread to one of those lab-coated ratbags who’s stolen it from me before,“he said. “What sort of bird-brain do you think I am?”
“So why,” I asked, “are you willing to trade with experimenters whom you have seen tricking your fellow crows?”
“Am I being paid for this interview?” he asked. “Sorry, no,” I said. “It’s for science.” “No cheese, no answer,” he cawed and our chat abruptly ended.