Alexander Nassar, associate editor of the science section
As schools re-open their doors to students, teachers and staff, the world shifts from carefree summertime to the hustle and bustle of everyday life, and each one of us delves into our own academic ventures. But what about our pets at home and other animals, left to their own devices, and separated from the world of academia? Well, decades of research have produced various forms of evidence for animal intelligence, encompassing species from many classes of the kingdom.
Why are animals “intelligent”?
Before listing the unexpected ways animals display their intellect, it is worth reflecting on the nature of intelligence, and what it means to be intelligent. Does it require mathematical skill? A symbolic system of communication? The elaborate use of the visual sense, a.k.a. arguably the most relevant in the domain of human intelligence? These are some of the core principles underlying the human species’ perception, understanding, and form of intelligence. But these principles are not universally shared by all species, and denying all other forms of intelligence on the basis of being different from our own is unethical. As per philosopher Peter Singer, that would be speciesism, where “the speciesist allows the interests of his own species to override the greater interests of members of other species”. Instead, the utilitarian philosophy endorsed by Singer and pioneered by Bentham in the eighteenth century focuses on sentience. Beings that have sentience, the ability to suffer and the drive to avoid it, are worthy of moral consideration. It is apt, here, to quote Gandhi: “The greatness of a nation and its moral progress can be judged by the way its animals are treated.”
Ravens, Crows and Parrots: the smartest of birds
Here are some interesting and surprising studies that outline the intelligence of several species of birds, once thought of as simple-minded animals, but brilliant in their own way for the purposes of their own evolutionary journey.
Ravens are capable of making plans for the future. A paper published in Science a few years ago describes a series of experiments that provided evidence for ravens making choices that facilitate their future. For instance, after exploring several tools including one that opened an apparatus containing a treat, ravens could successfully hold on to the useful tool for fifteen minutes and up to seventeen hours before getting access to the apparatus and opening it. Choosing to hold on to the right tool allowed the ravens to access food in the (near) future.
Ravens can also engage in profitable exchanges. The same paper included experiments where the ravens had to exchange a specific token out of several to get a treat, and they could hold on to the right token to later exchange it for a treat. Ravens successfully held on to the tokens for fifteen minutes and up to seventeen hours before they had the opportunity to exchange it for food. This again demonstrates that ravens make choices in the present that are useful to them in the future.
These exchanges can be strategically planned to obtain greater rewards. In further experiments, the ravens successfully resisted choosing a treat and instead chose a tool to open an apparatus with a greater reward inside or a token to exchange for a greater reward later on.
Crows remember their enemies. In another, rather gloomy study on Crows, masked people walked into the habitat of crows holding a dead crow in one hand and offering food with the other. The crows later attacked and harassed the people that had once carried a dead crow even when they came back carrying only food. Crows therefore hold a grudge against those who once seemed to be predators. This isn’t surprising, as the sight of another from one’s own species is naturally alarming, and a clear indicator of danger and death. In fact, it was found that the memory that crows have of those people is engraved in the danger learning center of their brain in the hippocampus and cerebellum.
Crows recognize the faces of their human enemies. In a similar study on Crows, but specific to face recognition, a series of distinctive masks were used when capturing crows. Crows could later identify, and scold, a person wearing that mask even when worn by different people, or when the mask was worn with accessories such as a hat.
African Grey Parrots have human-grade perception. Griffin, a parrot trained by Harvard psychologists, was reported in the Harvard Gazette to be able to see the Kaznizsa triangle, a renowned psychovisual illusion of three packman shapes forming the corners of an otherwise invisible triangle, and to identify occluded shapes based on previous knowledge of the number of corners these shapes had. Ken Nakayama, one of the professors who trained Griffin, noted that this accomplishment is remarkable because of what it entails. If Griffin could identify occluded shapes printed on paper, it means that he understands that the flat, 2D image he sees is a representation of several 3D objects. This is a key ability that no artificial intelligence machine has yet been able to do, bridging 2D images to 3D reality and solving perceptual problems such as the Kaznizsa triangle.
So, birds can plan ahead, remember their enemies, hold grudges and solve visual illusions even humans might succumb to… and were an exhaustive list of all such skills be made for all animal families, surely it would endorse the principle of animal intelligence.