A study published in the Science journal even claims that they can count out loud.

Researchers at the University of Tübingen, Germany, came to this conclusion after training carrion crows (Corvus corone) to produce a precise number of calls corresponding to a number, between one and four, that appeared on a screen.

Once they had finished cawing, they had to click on the screen to confirm their answer. If the answer was correct, the crows received a treat as a reward.

As it turned out, the crows were correct in most cases. The few errors were due to inattention, as the birds sometimes lost track of the calls they had already made or had yet to make. Despite this, their success rate in this exercise was so high that academics claim it was no coincidence.

“This indicates that, from the information presented to them, the crows form an abstract numerical concept which they use to plan their vocalisations before emitting the calls,” explains study co-author, Professor Andreas Nieder, quoted in a news release.

The conclusions of this study may seem anecdotal, but they show that crows, like humans, may be capable of mental arithmetic. Theoretically, this mathematical ability could be due to the same neural mechanisms in both species.

Studying corvids could therefore help the scientific community better understand the factors that have contributed to the evolution of this cognitive ability. Indeed, there’s every reason to believe that counting aloud is not the exclusive preserve of humans.

Crows have been known to be very astute, but their intelligence may be far more sophisticated than previously imagined. This is all the more surprising considering that these birds are endowed with a brain that weighs barely a few grams. In comparison, the average human brain weighs 1.4 kg.