African gray parrots will help other members of their species in need, the first time such charitable behavior has been documented among birds.

Scientists already knew African grays are particularly clever, with large brains and exceptional problem-solving skills. But they wondered if these birds—separated from great apes by some 300 million years of evolution—also possess complex social abilities, like helping one another. Corvids, another group of so-called “intelligent” birds that includes crows and ravens, have so far failed to demonstrate this ability, says Désirée Brucks, a biologist at the Swiss Federal Institute of Technology in Zürich.

“Parrots had not been tested yet,” says Brucks. “So it remained an open question of whether an ability to help each other proactively may not have evolved within birds.” (Read how the African gray is in danger of going extinct in the wild.)

Brucks and colleague Auguste von Bayern, of the Max Planck Institute of Ornithology in Germany, placed many paired combinations of eight African grays into glass enclosures, with a hole cut in a dividing wall that allowed the two birds to interact. The scientists then trained the parrots to trade metal tokens to a person via another hole in exchange for nuts.

When one parrot had all the tokens, it would assist its tokenless partner by gifting some of them through the dividing wall. The parrots tended to give more tokens to friends and family, but would also help parrots they had never met. Importantly, the parrots didn’t help when their partner was blocked from accessing the experimenter, suggesting they could recognize when their assistance was needed, or even useful.

This behavior, detailed in their study, published this week in the journal Current Biology, is possibly a consequence of evolving in giant, shifting flocks where an altruistic reputation is helpful, the authors say.

Katherine Cronin, a zoologist at the Lincoln Park Zoo in Chicago, lauds the study for ruling out simple playfulness as an explanation for passing the tokens. “We can be pretty confident that the African gray parrots are considering the benefits available to their partners,” Cronin says.

View Images African gray parrots Nikki and Jack exchange tokens with one another during a recent experiment. Photograph by Anastasia Krasheninnikova

She adds the research adds to growing evidence of selflessness across the animal kingdom—and reminds us the trait is not unique to humans.

Chimpanzees and bonobos

Some of the clearest examples of unprompted helpful behaviors come from our closest kin: chimpanzees and bonobos.

There’s evidence that chimpanzees can evaluate the needs of another chimpanzee in a predicament and respond by sharing an item that would solve the problem. For instance, captive chimpanzees have been observed providing a partner the appropriate tool they’d need to access a treat. (Read how chimps use "spears" to hunt mammals.)

“This study is similar [to the parrot study] in that the chimpanzees also helped dependent upon the need of the partner, and without personal gain,” notes Cronin.

And bonobos, an endangered species of great ape native to Africa, will freely donate their food to a stranger.

Vampire bats

Don’t let the razor-sharp fangs fool you—vampire bats have a soft side.

The small mammals are remarkably generous with their blood meals, regurgitating some of it for other bats in desperate need of sustenance—regardless if they're family.

In fact, whether or not a bat had received a previous food donation is much more important than relatedness for predicting if that animal will share food.

Norway rats

The humble Norway rat is one of the few animals to not only help other members of its species, but remember who has helped them, reciprocating the aid. In experiments published in 2015, researchers trained rats to donate either a high-quality treat (a banana) or a low-quality treat (a carrot) to another rat.

When the researchers provided the receiver rats the opportunity to return the favor by dispensing cereal, rats that gifted bananas got their cereal faster. (Also read how rats can show regret.)

Humpback whales

Watch wild dolphins help fishermen—and get a reward Study finds a tight social bond among dolphins that hunt fish alongside fishermen.

Mauricio Cantor, National Geographic Grantee

These cetaceans have the mysterious habit of interfering with orca hunts by placing themselves between the pod and the quarry, thrashing their imposing flippers and tail flukes if the orcas get too close. Humpbacks have been observed protecting seals, sea lions, and other whale species from the predators.

It’s unclear if this behavior helps the humpback in any way, though their defensive tactics could stem from the fact humpback calves are regularly targeted by orcas.