Crows May Grasp Basic Geometry: Study Finds the Brainy Birds Can Tell the Difference Between Shapes

Scientists tested crows on their ability to recognize “geometric regularity,” a skill previously assumed to be unique to humans

Sarah Kuta - Daily Correspondent

April 14, 2025



Carrion crows (Corvus corone) can tell the difference between geometric shapes, according to new research. Pexels


Crows are arguably among the smartest creatures on the planet, possessing some cognitive abilities that rival those of 5- to 7-year-old human children. Now, a new study adds basic geometry to the list of subjects these brainy birds seem to be able to master.

In a paper published in the journal Science Advances last week, researchers report that carrion crows can recognize “geometric regularity,” meaning they may discern traits like length of sides, parallel lines, right angles and symmetry. In the study, they could tell the difference between shapes like stars, crescents and squares, as well as between squares and irregular figures with four sides.

Researchers once thought this ability was unique to humans. But the findings suggest that’s not true—and they hint at the possibility that other species may be capable of similar feats, too.

“The crows show a sort of intuitive, strictly perceptual recognition of geometric properties,” says Giorgio Vallortigara, a neuroscientist at the University of Trento in Italy who was not involved with the work, to Scientific American’s Gayoung Lee.

To test the birds’ mathematical abilities, scientists in Germany placed two male carrion crows (Corvus corone) in front of a digital screen in a laboratory. They displayed six shapes on the screen, then trained the birds to peck at the outlier—the one that looked different from all the others. Whenever the birds chose correctly, researchers rewarded them with a tasty snack, either a mealworm or a bird seed pellet.

More:
https://www.smithsonianmag.com/smart-news/crows-may-grasp-basic-geometry-study-finds-the-brainy-birds-can-tell-the-difference-between-shapes-180986425/