Crows have shown an ability to geometry — it was believed to be an exclusively human ability

German scientists from the University of Tübingen have made sure that crows are able to distinguish between regular and irregular geometric shapes.

For a long time, scientists have been convinced that the understanding of right and wrong geometric shapes is a purely human brain property, but it turned out that this is not the case. People have an innate ability to understand symmetry and asymmetry. Young children build with cubes and draw rectangles even before they learn to understand letters.

German scientists Philip Schmidbauer and Andreas Nieder decided to conduct an experiment with two crows, who were 10 and 11 years old, respectively. They were trained to recognize a visual shape that would be different from a number of others. In particular, at first it was a red spot among a group of green spots and a pattern with sharp corners among a series of smooth patterns. And it turned out to be a fairly easy task for the crows.

After that, the crows were shown images of six quadrilaterals, five of which were regular in shape, and the sixth had an irregular angle.

Crows have never been taught to pay attention to angles or symmetry. However, they chose an irregularly shaped shape much more often than if it were a mere chance.

Of course, animals are able to orient themselves in space. They memorize certain routes and recognize places they have visited. However, most scientists were convinced that animals are not capable of understanding geometric patterns. It is known that crows, ravens, and jays belonging to the passerine family are able to recognize themselves in a mirror, plan future actions, and use sophisticated tools in the course of their own activities. Some researchers have even compared these birds to chimpanzees in terms of their mental abilities.

The brains of crows are not at all like those of humans or monkeys. In particular, they don’t have a structure called the neocortex, the six layers of which store most abstract mammalian thoughts. However, these birds do have a mantle, and something very similar to abstract thinking is probably stored there.

These birds are forced to visually assess the shapes and placement of objects such as tree branches very quickly in flight, crevices, etc., for safe orientation, landing, and searching for food. Symmetry recognition can help crows determine the suitability of certain branches for nesting.

In 2021, a similar experiment with the recognition of symmetrical and asymmetrical geometric shapes was conducted with baboons. Despite intensive training, these animals did not demonstrate the ability to detect geometrically irregular shapes.

The authors of the study concluded that some forms of thinking especially those used to navigate in complex environments, may not require the same brain structure as mammals. For example, bees can count to at least four, parrots imitate human speech in a way that implies understanding, dolphins recognize themselves in mirrors, and crows can understand asymmetrical geometric shapes.

Andreas Nieder believes that there are other types, that have this ability and that need to be studied. But he also calls for more in-depth study of the crow brain. It is important to understand why we share such fundamental skills with creatures that are so different from us, and how these skills evolved.