(This is for a midterm and only needs four questions and each a single answer) Feathered friends: Study shows "selfless" parrots helping peers

African grey parrots help their peers complete tasks despite no immediate benefit to themselves, researchers have found, in the first study to show that birds display such apparently "selfless" behavior.

While other prosocial behaviors have been seen in birds, the team say helping peers to achieve a goal, so-called "instrumental helping," has only previously been shown outside of humans in orangutans and bonobos.

Désirée Brucks, a co-author of the paper from Max Planck Institute for Ornithology, said it was an obvious choice to try an experiment with parrots.

"Parrots and corvids, crows and ravens, are really known for being the brightest birds around. They are often referred to as 'feathered apes' and they have been tested in many studies on problem-solving or word learning," she said.

However, the bonhomie does not extend to all birds, or even all parrots: a previous study has shown that ravens do not help their peers complete a task, while the new research shows blue-headed macaws are also rather selfish.

The team says their findings suggest the helpful behavior cropped up multiple times over the course of evolution.

"It seems that potentially similar social and ecological pressures on mammals and also birds lead to the development of similar behaviors," said Brucks.

Writing in the journal Current Biology, Brucks and colleagues report how they tested two parrot species in a task that involved the birds passing a token, in the form of a metal ring, through a hole in their compartment to a neighboring bird of the same species. This token could then be passed by the second bird to a human, via another hole, who would exchange it for a piece of walnut.

In total, eight African grey parrots and six blue-headed macaws were involved in the experiments. All were trained individually to exchange the tokens for food when a human held out their hand.

The team found African grey parrots helped their neighbors by passing tokens to their neighbor when a human held out their hand, allowing the second bird to drop it through the hole and receive a tasty treat.

The same behavior was seen when the roles of the birds were reversed. The more tokens a bird had previously given, the more they received in return.

However, the team stressed, the birds did not know at the outset that their favor would be reciprocated, suggesting it is something of a "selfless" act.

Far fewer tokens were passed between birds when there was no human signal and no hole for them to exchange the token — suggesting the parrots did not simply pass tokens for fun. The parrots also passed fewer tokens to the second compartment when there was no neighbor present.

When the experiments were repeated with blue-headed macaws, the birds rarely passed tokens to their neighbor.

The upshot, the team says, is that the African grey parrots were helping peers to achieve their task, adding the behavior is more complex than simply sharing food with a neighbor since it involves understanding the needs of another bird for the latter to achieve their goal.

The team says the differences between the species may be down to African grey parrots gathering in huge flocks at night but splitting into smaller groups during the day to forage. Brucks said such behavior is thought to require strong social cognitive abilities, adding that being helpful might help the birds gain a good reputation with their peers, making it more likely they would team up for foraging and other tasks.

By contrast, reputation might not be important to blue-headed macaws as they live in smaller, more stable flocks, possibly with a more hierarchical structure and a lower emphasis on sharing resources. Indeed, in another task, the team found these birds were less keen than African grey parrots on sharing a bowl of food with their peers.

Manon Schweinfurth, an expert in animal behavior from the University of St. Andrews, who was not involved in the work, said evidence of reciprocal behavior in African grey parrots is fascinating. "It has been thought that it is so cognitively demanding that only humans can show it. [But] we now get more and more evidence from other animals that they are able to show reciprocity," she said.

Schweinfurth added that the finding that some birds, as well as some mammals, show instrumental helping might be rooted in the fact that birds feed their young.

"It is in their behavioral repertoire to hand over things to [members of the same species]," she said.