Parrots can perform impressive feats of intelligence, and a new study suggests that some of these "feathered apes" may also practice acts of kindness.
African grey parrots voluntarily helped a partner get a food reward by giving the other bird a valuable metal token that could be exchanged for a walnut, according to a newly published report in the journal Current Biology.
"This was really surprising that they did this so spontaneously and so readily," says Désirée Brucks, a biologist at ETH Zürich in Switzerland who is interested in the evolution of altruism.
Children as young as 1 seem highly motivated to help others, and scientists used to think this kind of prosocial behavior was uniquely human. More recent research has explored "helping" behavior in other species, everything from nonhuman primates to rats and bats.
To see whether intelligent birds might help out a feathered pal, Brucks and Auguste von Bayern of the Max Planck Institute for Ornithology in Germany tested African grey parrots. They used parrots that had previously been trained to understand that specific tokens, in the form of small metal rings, could be traded for a food treat through an exchange window.
In their experiment, this exchange window was covered up and closed on one bird's cage, making it impossible for that bird to trade. The bird had a pile of tokens in its cage but no way to use them. Meanwhile, its neighbor in an adjacent cage had an open exchange window — but no tokens for food.
After sizing up the situation, the token-rich bird would help out its pal by passing tokens through an opening between the two bird enclosures. And the bird shared even though it didn't partake in the walnut payoff.
"The African greys gave the token beak-to-beak with their partner," Brucks says. "It was not just one token. Many of them transferred all 10 tokens, one after the other, always watching how their partner got the food for it, whereas they themselves did not get anything."
Later, scientists reversed birds' roles to see if the recipient of this generosity would pay back those favors. And the birds did.
"In the very first trial, they could not have known that the roles would be reversed afterward," says Brucks, who notes that the parrots seemed to have an intrinsic desire to help out their partner. The eight birds tested all knew each other and lived in the same social group.
It seems that the birds weren't just being playful with the tokens, but really understood when and why the token was needed. That's because the birds would rarely pass a token over if the neighbor bird's exchange window was closed up.
This study is a starting point to explore what exactly is going on in the birds' minds, Brucks says.
A similar study in ravens did not find this effect. And when Brucks tested blue-headed macaws, they weren't helpful either. The macaws tried to bring the tokens as close as possible to the experimenter but did not transfer the token to the partner, Brucks says.
"We are really interested in this topic, and it's an important topic. The problem is it's very, very hard to design an experiment to truly demonstrate what is truly going on with these animals," says Irene Pepperberg, a Harvard researcher whose work with a famous African grey parrot named Alex helped reveal the sophisticated cognitive abilities of these birds.
Pepperberg has also done experiments to test African greys' willingness to help, using a different setup, and found that one parrot appeared to have some understanding of sharing — but it didn't seem like the parrots were spontaneously super-altruistic.
Still, Peggy Mason of the University of Chicago believes that this new study in parrots is striking.
"When they gave the token, the other bird was getting the food and they were not," Mason says. "I think they had the sense that this was a useful token, and that this token would turn into food for the other bird. It's very shocking. It's surprisingly giving, just because the only thing the bird doing it gets is that warm glow of helping."
ARI SHAPIRO, HOST:
Some parrots are super smart, but are they helpful? NPR's Nell Greenfieldboyce reports on a surprising new study.
NELL GREENFIELDBOYCE, BYLINE: Imagine that you are an African grey parrot. You're sitting in a cage with a bunch of small metal tokens. You know that these tokens can be traded through a window for a tasty walnut. But the trading window in your cage is closed, shut tight. Meanwhile, there's another parrot in the cage next door. You can see that its trading window is wide open. But this bird has no tokens.
DESIREE BRUCKS: One has the tokens but cannot do anything with them, whereas the other one needs the tokens in order to get food.
GREENFIELDBOYCE: Desiree Brucks is a researcher in Switzerland who did this study. She found that the parrots would spontaneously help out their neighbor by going to an opening between the two cages and selflessly handing a token over - well, beaking (ph) it over.
BRUCKS: Many of them transferred all 10 tokens, one after the other, always watching how their partner got the food for it.
GREENFIELDBOYCE: This study in the journal Current Biology shocked Peggy Mason. She's a researcher at the University of Chicago who studies helping behavior in rats. She says the generous parrots got no food, only the warm glow of giving.
PEGGY MASON: That's amazing.
GREENFIELDBOYCE: Still, in other lab tests of sharing, this species hasn't been so super generous. Irene Pepperberg studies African greys at Harvard. She says it's hard to design experiments to truly show what's going on in these animals' brains.
IRENE PEPPERBERG: I mean, we are really interested in this topic, and it's an important topic.
GREENFIELDBOYCE: Because humans aren't the only ones who know it's better to give than to receive. And scientists want to understand how this evolved.
Nell Greenfieldboyce, NPR News. Transcript provided by NPR, Copyright NPR.