Research Reveals Intelligent Birds Can Distinguish Between Shapes

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New research reveals that crows can discern geometric patterns, challenging the idea that this skill is exclusive to humans

Sarah Kuta – Daily Correspondent

April 14, 2025 4:11 p.m.

Crows have long been recognized for their impressive intelligence, often compared to that of young children. A recent study has broadened our understanding of their cognitive skills by demonstrating that these birds can grasp fundamental concepts of geometry.

In a study published in the journal Science Advances, researchers found that carrion crows (Corvus corone) are capable of recognizing “geometric regularity.” This skill allows them to identify characteristics like the lengths of sides, symmetry, paralleling lines, and angles. The crows demonstrated their ability to differentiate between various shapes, including stars, crescents, squares, and irregular quadrilaterals.

Traditionally, the ability to comprehend geometry was considered a trait unique to humans. However, these findings suggest that other species might possess similar cognitive skills.

“The crows display an intuitive understanding of geometric properties, purely from a perceptual standpoint,” explained Giorgio Vallortigara, a neuroscientist at the University of Trento in Italy, to Scientific American.

To evaluate the crows’ geometric capabilities, scientists conducted experiments in Germany involving two male carrion crows in a controlled environment. A digital screen displayed six shapes, and the crows were trained to peck at the shape that differed from the others. In return for correct selections, they were rewarded with treats, such as mealworms or bird seed pellets.

Initially, the researchers presented obvious outliers—like a single flower mixed with several crescents. As the crows became accustomed to the task, the complexity increased, requiring the birds to differentiate between more subtly distinct shapes such as squares and parallelograms.

Remarkably, even as the challenges intensified, the crows continued to accurately identify the outlier shapes, maintaining their performance even after the treats ceased.

While researchers have not definitively determined why crows possess this ability, it is hypothesized that recognizing shapes may aid in navigation during flight, assist in locating food sources, or help them identify individuals, such as mates, through facial recognition.

“These capabilities have evolved from a biological standpoint to provide survival or reproductive advantages,” stated Andreas Nieder, a neurophysiologist at the University of Tübingen in Germany, to Scientific American.

Future research aims to explore the specific brain regions that enable these birds to excel in geometry. Unlike humans, birds lack a cerebral cortex in the same way, which is crucial for advanced mental functions in humans. Nevertheless, crows exhibit comparable cognitive abilities, suggesting alternative mechanisms at work in their brains.

“Evolution has evidently discovered different pathways to produce adaptable animals,” Nieder commented.

Researchers also intend to examine geometric recognition abilities in other species. Previous experiments with baboons have not yielded the same level of mathematical understanding despite thorough training.

It is widely believed that crows and humans are not the only species capable of geometric reasoning. “This opens up a new area of exploration within animal intelligence,” Nieder noted.

Crows have established themselves as intellectual leaders in the animal kingdom. Prior studies reveal their skills in counting, voice discernment, facial recognition, and even creating tools for future utility. Their cognitive abilities challenge the long-standing view that advanced intelligence is exclusive to humans.

“Humans certainly do not have a monopoly on complex cognitive skills,” emphasized Heather Williams, a biologist at Williams College, when discussing animal intelligence with CNN. “It is unsurprising that crows demonstrate such intelligence.”

Source
www.smithsonianmag.com