We all know that birds are smart. Amongst birds, however, ravens are at the top when it comes to intelligence. The black bird even tops the list of most intelligent animal species in general. Pretty impressive, right? Cognitive biologists at the University of Vienna decided to test just how smart these birds are when it comes to cooperation.
The study, which was published in Scientific Reports, gave two ravens the ends of a piece of rope. The birds had to pull the ends of the rope so that a platform with two pieces of cheese (one for each bird) on it slid within their reach. If only one bird pulled, the rope would come undone from the platform and neither bird would get any cheese. The untrained ravens worked it out on their own, solving the task through cooperation. The researchers discovered, however, that this only worked when the birds were “friends.?If the birds did not like each other, they were uncooperative. For example, if one bird happened to cheat and take both pieces of cheese for himself, the other bird would not cooperate in further trials in which he was paired with the cheating bird.
Jorg Massen, the lead author of the study, said in a press release, “From the wild, it was already known that ravens are able to cooperate when, for example, mobbing predators. But using an experimental set-up working with captive ravens now allowed us to investigate how exactly they do so.?Regarding the cheating birds and the subsequent behavior of the victim, Massen added, “Such a sophisticated way of keeping your partner in check has previously only been shown in humans and chimpanzees, and is a complete novelty among birds.”