You better be nice to ravens — or they’ll remember you treated them badly next time they see you. According to a recent study, ravens (Corvus corax) can distinguish and remember people who treated them unfairly in the past shedding more light on the complex social lives of some of the most intelligent creatures on there.

Don’t be a dick with ravens, like this fox. Illustration by Arthur Rackham.

A raven’s grudge

In the classic Aesop fable “The Fox and the Raven”, a raven is tricked by a sly fox into dropping the delicious piece of cheese from its beak. The fox flatters the bird asking it to sing or speak, depending on the variation of the story. ‘You were not dumb, it seems, you have indeed a voice; you have everything, Sir Crow, except brains,’ says the fox who runs off with the yummy morsel.

The truth is ravens have plenty of brains. These birds score on par with chimps on cognitive tests, use gestures to point out things and communicate, they can also tell if someone’s looking at them or not and can remember people’s faces.  In one logic test, the raven had to get a hanging piece of food by pulling up a bit of the string, anchoring it with its claw, and repeating until the food was in reach. Many ravens got the food on the first try, some within 30 seconds. In the wild, ravens have pushed rocks on people to keep them from climbing to their nests, stolen fish by pulling a fishermen’s line out of ice holes and played dead beside a beaver carcass to scare other ravens away from a delicious feast.

As for the fox in Aesop’s fable, it better be careful next time. According to a new paper published in the journal Animal Behavior, ravens learn to prefer trainers who have treated them fairly over those who have ripped them off.

The conclusion was reported by researchers in  Vienna and Sweden who trained common ravens to trade crust of bread for a morsel of cheese with human partners who acted as the broker. After this initial round, the researchers observed what happened when the birds dealt with ‘fair’ and ‘unfair’ partners. The latter humans would simply keep the bread after it was offered by the raven and scandalously ate the cheese. Trick me once but you won’t trick me twice, the raven must have thought. Indeed, the ravens purposely avoided the cheating humans in separate trials a month later. This can only mean that ravens not only have a sense of fairness, they hold grudges for at least a month too, signaling a fine memory. They likely hold on to these grudges for far longer than a month, much like my ex-girlfriend.

Ravens aren’t the only non-human animals with a sense of fairness. Dogs and wolves share it, as do chimpanzees and likely many other creatures.