Ravens Have A Sense Of Fairness And Memory
In recent years, various studies have given us some insight into exactly how complex and advanced crows and ravens are in terms of their cognitive abilities. For example, these birds were already shown to identify inequity and act accordingly. Similarly to us, ravens were also shown to actively choose to cooperate with friends. Finally, previous studies found that American crows can remember the face of a dangerous human for several years after just one interaction. Although the mechanism behind such complex behaviours is still unknown, researchers hypothesize that such extraordinary capabilities might rely on elaborate memory systems.
Researchers from three European institutions joined forces to add to the knowledge base of raven memory abilities. They carried out tests where the birds could exchange a low-quality food item for a high-quality one. These birds got first-hand experience by interacting with the human experimenters, but there were also birds who observed these interactions from an adjacent compartment, separated from the experimental room. Specifically, the scientists were interested in learning if ravens remember reliable ‘fair’ experimenters and those who would not reliably exchange (i.e. the ‘unfair’ experimenter), and if later on they would choose to interact with ’fair’ experimenters more when given the choice.
The study found that ravens with first-hand experience were more likely to interact with experimenters with whom they had had a positive previous experience, and that this memory lasted at least 1 month. In contrast, observer birds did not distinguish between the experimenters when given the choice to interact with them. We must remember that the exchange came at an initial cost for the birds, as they were required to give the low-quality food item away. During the training period, the cost was always outweighed by the gain of a better reward; however, during the experiment, the ravens experienced that giving food away bears the risk of getting nothing in return. These results suggest that ravens can rely on their memory from one single interaction sequence when it comes to evaluating direct reciprocity and risk associated with such exchanges.
The researchers showed successful reciprocal interactions of ravens with human experimenters. Nevertheless, the team urges for alternative study designs to test the reason for the failure of the observers in this test. More and more studies are being published which show the outstanding mental capacity of corvids, bridging the gap between how humans and other animals experience life. Advocates should find it easier to introduce the topic of bird well-being and protection when armed with such compelling information on their cognitive capabilities and similarities to those of our own.