Crows Can ‘Count’ Similarly to Toddlers, Demonstrate Numerical Skills Through Controlled Vocalizations

Crows are already known as one of the smartest animals in the world, but a new study suggests that these animals can actually count out louds in a similar way to human toddlers.

How Is Counting Learned?

The ability to count out loud, or to recite numbers, is distinct from understanding numbers. It does not only require understanding, but also needs purposeful vocal control with communication as the goal. In humans, speech is used to symbolically count and communicate quantities, a complex ability that is developed in childhood.

Symbolic counting involves relating specific words to specific quantities. Before mastering this skill, human toddlers usually need to produce a number of speech sounds that match the quantity of the objects they see.

As toddlers learn to count, they can take a bit of time to master learning the specific number connected with specific quantities. While children gradually learn this skill, they can sometimes use random numbers to produce a vocal tally.

Intelligent Thinking Among Crows

At the University of Tübingen in Germany, a team of researchers has discovered that crows can count out loud by producing a specific number of caws. The details of their study are discussed in the paper "Crows 'count' the number of self-generated vocalizations."

There are other animals, like honeybees, which have shown the ability to understand numbers. However, the specific manifestation of numeric literacy has not yet been observed in any other non-human species.

Whether this ability exists in animals other than humans is not yet known. To answer this question, a team of researchers led by neuroscientist Diana Liao trained three crows to produce one to four vocalizations in response to visual and auditory cues.

The biological origin of symbolic counting remains a mystery, but since crows are known to understand difficult number concepts, Liao and her fellow researchers believe these animals represent a good candidate for investigating more complex numerical skills.

In each trial, the crows were encouraged to make a certain number of vocalizations and indicate the end of the vocal sequence by pecking at a target. It was found that these glossy black birds have the ability to produce a specific number of vocalizations successfully and deliberately in response to different cues. Such a degree of control is not yet observed in any other animals.

According to the authors, the crows seem to plan the number of vocalizations before starting. It was shown that the timing and features of the first vocalizations predicted the overall number the birds were about to count to. Meanwhile, each 'number' had different acoustic features compared to others.

This pattern is almost similar to how counting 'one,' 'two,' 'three', and 'four' sound different in human speech. This complex ability demonstrated by crows mirrors the enumeration skills of toddlers shown before they learn to understand cardinal number words.

The recent finding may also constitute an evolutionary precursor of true counting where numbers are considered part of a combinatorial symbol system. Previous research reveals that crows are just as smart as apes in terms of using tools and thinking logistically. These abilities include delayed gratification and reasoning, and the ability to feel empathy and recognize themselves in the mirror.