You do not mess with ravens. Because if you dupe them, they will remember.
Image: Tomas Quinones/Flickr
Or so says a team of Austrian and Swedish scientists. In a small study on captive-bred ravens, they found that the birds remembered when scientists tricked them out of getting a good treat. Such a study has important implications for understanding the social dynamics of these birds, ones that we already know are super smart.
"We see many aggressive interactions and socially positive interactions" in wild ravens, Matthias Loretto, researcher from the University of Vienna who was not involved with the study but has worked with the authors on other research, told Gizmodo. "In this context it makes perfect sense that they would remember about past interactions with other individuals."
The researchers behind this study basically wanted to test raven memory as it relates to fairness -- whether they'd remember single positive or negative interactions. They used nine human-raised ravens (named Tom, Laggie, Horst, Louise, Nobel, George, Paul, Joey and Rocky if you were wondering) to see just what the birds remembered. The ravens were trained to exchange bread for cheese, a preferred snack based on the scientists' observations.
The researchers started the trials by putting two birds into the experimental area, the subject and an observer. They trained the birds to offer bread to humans, who would either be fair and give the birds cheese in return, or unfair and eat the cheese themselves. The researchers used various combinations of experimenters to perform different experiments.
Two days and two months later, they performed a new set of trials, including one where each raven was given bread and presented three experimenters -- the fair one, the unfair one, and one they hadn't seen before. At both later trials, all but two birds remembered and picked the fair experimenter, demonstrating that the birds remembered these single negative experiences. The researchers didn't see a noticeable effect above chance for the observing birds, though. The team published their result recently in the journal Animal Behaviour.
Sure, this is a small experiment with a lot of moving parts and a small sample size, and is ultimately between a bird and human trainers instead of between birds. But Loretto said he was convinced. "This is a very artificial, human experiment," he said, but "I observe ravens so often in the field that it makes absolute sense that they would remember." The study further adds evidence to his own study, tagging wild ravens with GPS trackers to demonstrate that the birds meet with others that they like at different locations.
The next step, he said, would to be to test the memory of ravens interacting with other ravens.
But the most important take away here is that you do not mess with ravens. Because they remember.