By Dr. Karen Shaw Becker
Ravens belong to the corvid family along with crows, magpies, jackdaws and jays. These birds are known for their uncanny intelligence that's far above that of most other birds and even many mammals. With cognitive abilities similar to those of apes and dolphins, it's been shown, for instance, that crows recognize individual human faces. What's more, they readily express their displeasure toward "dangerous" faces that may have trapped them in the past while displaying more acceptance for neutral faces.1
Ravens have similarly good memories, including for those who have wronged them in the past. In recent research published in the journal Animal Behavior,2 a series of experiments revealed that ravens can recognize who's fair and who's not — and act accordingly.
Ravens Prefer Trainers Who Treat Them Fairly
For the study, nine ravens who had been raised in captivity were trained to exchange a piece of bread for a more coveted piece of cheese. During the "fair" part of the study, ravens received a piece of bread crust from one trainer then carried it over to another trainer, who would take the bread and give the raven the cheese. In the next "unfair" phase of the study, the same procedure was followed, but the trainer ate the cheese instead of giving it to the raven.
The ravens, likely upset by the researchers' betrayal, "appeared to react in a 'frustrated' way to the behavior of the unfair experimenter. They started vocalizing, showed increased activity, and cached or ate the remaining pieces of the low-quality reward," the study noted.3 Two days later, the scenario was carried out once again, this time with the fair trainer, an unfair trainer and a third neutral trainer for the birds to choose from.
Six of seven ravens in the experiment chose the fair trainer while one chose the neutral trainer. One month later, the birds still remembered who had done them wrong; of nine ravens tested, seven chose the fair trainer, one the unfair trainer and one the neutral trainer. While another raven was also in the cage, observing the experiments, it didn't seem to remember the exchanges in the same way as the participating bird.
Still, the study shows that ravens remember when they're treated fairly for at least a month and prefer to interact with those who were just, which could have significant implications for birds in the wild. According to National Geographic:4
"In the wild, where ravens don't rely upon a bread and cheese economy, the study offers insights into how corvids' complex social structure evolved. 'If one individual supports another, there's a correlation between support given and received on a long-term basis,' said [study co-author Jorg] Massen [Ph.D. of the University of Vienna].
In other words, ravens build up social capital that is reciprocated over time. Favors in the form of preening or aid during a fight are selectively given to ravens in good standing with one another."
Like Apes, Ravens Can Plan for the Future
It was long assumed that only humans were capable of thinking about and planning for future events. Then, it was revealed that great apes, like chimpanzees and orangutans, could do so too, choosing tools that would come in handy for them in the future. In 2007, it came to light that corvids appear to plan for the future as well.5
In a University of Cambridge experiment, western scrub jays were kept in rooms that either had plenty of nuts always available or no nuts available. When given access to nuts, the jays in the no-nut room stored three times more nuts than jays in the nut-filled room.
Skeptics brushed off the findings as more of an instinctual behavior than a sign of intelligence, but in 2017 researchers once again showed that corvids engage in so-called "flexible planning" that is quite intentional.6 Ravens were taught to open a puzzle box that contained a treat by putting a certain stone into a tube. Later, the birds were allowed to choose objects from a tray that included the important box-opening stone (among other objects).
About 86 percent of the time, the birds chose the stone over other objects, which came in handy when the puzzle box was brought back in 15 minutes later. In a similar experiment, ravens learned to exchange a blue bottle cap for food. When later offered a tray of various items, almost all of them chose the blue bottle cap, presumably in the hopes of later exchanging it for a treat.
This was true even when the tray contained a bit of food, which shows the ravens also exerted self-control. Such skills are not even seen in monkeys or children prior to the age of 4.7 Ravens also have complex interactions, which is made possible by their good memories and cognitive abilities. For instance, ravens remember former members of their group even after extended periods of time, as well as categorize their relationships with other birds.8
Interestingly, crows and jays even react and hold gatherings when a bird in their group dies. Western scrub jays, for example, seem to hold "funerals" for their dead in which they congregate in the area of the body and make loud, screeching calls for up to 30 minutes.9 Their intelligence likely plays a key role in how well these birds have adapted to modern life. While they were once widespread throughout the U.S., they were driven from the east and Midwest prior to 1900.
However, the Audubon reported that their range is expanding: "An intelligent and remarkably adaptable bird, living as a scavenger and predator, it can survive at all seasons in surroundings as different as hot desert and high Arctic tundra. Once driven from much of its eastern range, the raven is now making a comeback."10