African grey parrots are not only really smart, they are helpful too. They are the first bird species to pass a test that requires them both to understand when another animal needs help and to actually give assistance.
Besides humans, only bonobos and orangutans have passed this test, says Désirée Brucks at the Ludwig Maximilian University of Munich in Germany. Even chimps and gorillas have failed at it.
Brucks and her colleague Auguste von Bayern first trained birds one at a time. Each was given a pile of tokens – small metal washers – and taught that they could exchange them for food by passing them to a researcher through a small hole in a clear screen.
A month later, two birds were separated from each other and the researcher by clear screens. One bird was given a pile of tokens but the hole between it and the researcher was blocked.
The other bird’s hole to the researcher was open but it had no tokens. There was a third hole in the screen between the two birds, allowing them to pass objects through, as shown above.
Seven out of eight African grey parrots passed tokens through this third hole to birds without tokens, so those birds could swap them for food. They passed more tokens when the other bird was one they spend lots of time with – a “friend” – but still did it for birds they spend little time with.
If there was no other bird, they didn’t pass tokens through the hole. And if both holes to the researcher were closed so neither bird could exchange tokens for food, those with tokens passed far fewer to the other bird.
This test requires both intelligence and helpfulness, says Brucks. “They need to understand that the other bird is in need of help.”
The pair also tested blue-headed macaws, but found they didn’t help other macaws. In 2015, another team found that ravens didn’t help each other either.
It’s not clear why African greys help others, nor why other species of birds don’t. The African grey parrots with the tokens didn’t get any immediate benefit: only very rarely did the bird getting food give any to the bird giving them tokens.
Journal reference: Current Biology, DOI: 10.1016/j.cub.2019.11.030
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