A recent study reveals that crows possess numerical skills similar to those of young human children. They can count out loud, a discovery that marks a significant advancement in our understanding of animal cognitive abilities.
Researchers observed that rook crows (
Corvus corone) can produce a specific number of caws in response to visual or auditory stimuli, enabling them to count from one to four. The findings of this study were published on May 23 in the journal
Science.
To study this ability, the researchers subjected three crows to random visual and auditory stimuli, such as Arabic numerals and instrument sounds. Through trial and error, the birds learned to associate each signal with a precise number of caws. Once the number of caws was completed, the crows had to peck at the screen to indicate they were finished. A reward was given if the number of caws matched the signal.
Producing a specific number of vocalizations with intention requires a sophisticated combination of numerical abilities and vocal control, the researchers explain.
Our findings demonstrate that crows can flexibly and deliberately produce an instructed number of vocalizations using the "approximate number system," shared by humans and animals.
The crows' ability to count resembles that of young children, who use sounds to enumerate before understanding the words for numbers. This skill could be a precursor to the evolutionary development of true numeration, where numbers are part of a combined symbol system.
The numeration skills observed in crows, comparable to those of young children, show that they often count based on vocalizations of numbers rather than the numbers themselves. Even when they made mistakes, their errors often involved close numbers (like three and four) rather than distant numbers (like one and four), indicating some numerical understanding.
The researchers conclude that this ability of crows to count could constitute an evolutionary precursor to true numeration in humans, where numbers are integrated into a combined symbol system.