Crows Can Count Up To Four, A New Study Finds

According to a recent study conducted by a group of researchers from the Animal Physiology Lab at the University of Tübingen in Germany, crows can count up to four.

According to recent research, crows, a common urban bird, can loudly count up to four, so maybe calling someone “birdbrained” isn’t such a bad thing after all.

A new study done by a group of researchers from the animal physiology lab at the University of Tübingen in Germany shows that curious animals can not only count but also match the number of calls they produce when shown a numeral.

The technique that humans utilize to swiftly understand how many objects we’re looking at and to learn how to count as toddlers is comparable to how birds recognize and respond to numbers. The results, which were released on Thursday in the journal Science, contribute to our expanding knowledge of crow intelligence.

“Humans do not have a monopoly on skills such as numerical thinking, abstraction, tool manufacture, and planning,” said animal cognition expert Heather Williams via email. “No one should be surprised that crows are ‘smart.’” Williams, a professor of biology at Williams College in Massachusetts, was not involved in the study.

Crows aren’t the only animals in the animal kingdom that can count. Like young toddlers, chimpanzees have been trained to count in numerical sequence and recognize the significance of numerals. Some male frogs calculate the number of calls made by rival males to match or even surpass that number when it comes time for them to croak at a female. Even though the approach isn’t always reliable, scientists have speculated that ants use step counting to retrace their routes back to their nests.

According to the most recent study, crows can learn to correlate numerals with values and can count aloud by that understanding, just like young humans.

Can crows count much like toddlers do?

According to lead study author Diana Liao, a neurobiologist and senior researcher at the Tübingen lab, the research was motivated by toddlers learning to count. Toddlers count the number of objects in front of them by using phrases that represent numbers: Their counting may sound like “one, two, three” or “one, one, one” if they see three toys in front of them.

Liao wondered if crows could do the same. A June 2005 study on chickadees adjusting their alarm sounds to the size of a predator also served as inspiration for her. The study discovered that chickadees utilized fewer “dee” sounds in their alarm calls the longer the predator’s wingspan or body length. Conversely, for smaller predators, the songbirds would make more “dee” sounds if they came across a smaller bird, which may pose a bigger threat to chickadees due to their increased agility, according to Liao.

The number of sounds the tiny songbirds produced was either an involuntary response or something they were unable to regulate, according to the authors of the chickadee study. Liao was intrigued by the notion that crows, whose intelligence has been extensively studied for decades, would be able to control how many sounds they make, essentially “counting” like young children.

The crows planned their number of caws

Throughout more than 160 training sessions, Liao and her colleagues trained three carrion crows, a European species that is closely related to the American crow. The birds’ tasks during training involved teaching them to associate a range of visual and aural stimuli from 1 to 4 with the appropriate number of caws. In the example given by the researchers, a visual cue might be represented by a vivid blue numeral, and the associated audio could be a drumroll’s half-second song.

Within ten seconds of seeing and hearing the signal, the crows were supposed to produce the same number of caws as the number indicated by the cue, in this case, three caws for the cue with the number 3. The birds would peck at a “enter” key on the touchscreen that displayed their cues to indicate that they had finished counting and cawing. The birds would have received a reward if they had numbered properly.

It seems that the crows responded to each cue more slowly as the cues got stronger. As Liao noted, “more vocalizations were impending,” the crows’ reaction times accelerated, indicating that they had calculated how many caws they would produce before opening their beaks.

The first call the birds made revealed to the researchers how many calls they intended to make; small acoustic variations indicated that the crows were aware of the number of numbers they were observing and had combined the information.

“They understand abstract numbers … and then plan as they match their behavior to match that number,” Williams said.

Even the errors the crows made were very sophisticated: Liao and her researchers could tell from the sound of the first call where the crows had erred, such as when they had cawed too frequently, stammered over the same number, or delivered their answers with their beaks too soon. According to Williams, these are the “same kinds of errors humans make.”

We’re still learning how smart crows are

Animal behaviorist B.F. Skinner popularized the idea that birds and many other animals only made snap decisions based on cues in their immediate surroundings in the 20th century. However, new research by Liao and her colleagues reveals that crows can modulate their ability to synthesize numbers to make sound, adding to the body of data supporting this ability.

The results of the study team are highly specific but significant, according to Kevin McGowan, a researcher at the Cornell Lab of Ornithology in Ithaca, New York, who has spent more than 20 years studying wild crows in their natural environments. They challenge the once-common belief that all animals are simply stimulus-response machines. McGowan did not participate in the research.

Crows aren’t just basic, mindless machines that react to their surroundings; according to the study, McGowan told CNN, “they’re actually thinking ahead and have the ability to communicate in a structured, preplanned way.” It functions as a kind of prerequisite to language.

For many years, crow intelligence has been researched. Researchers have looked into how New Caledonian crows make their complex equipment to get food. According to a November 2013 paper coauthored by Andreas Nieder, the lead researcher in the University of Tübingen lab, the birds seem to set rules. Crow language’s vastly varied tones and emotions have also baffled specialists for decades, according to McGowan.

Liao et al.’s study isn’t even the first to investigate if crows are capable of counting. Irene Pepperberg, an expert in animal cognition, pointed out that Nicholas Thompson started this research back in 1968. The work that Pepperberg, a research professor of psychological and brain sciences at Boston University, has done with Alex, an African grey parrot, has made her most famous.

According to Thompson’s theory, crows were able to count by manipulating the length and quantity of their caws within a specific sound burst. He said that the crows’ capacity for counting “seems to exceed the demands which survival makes for such abilities.”

In September 2015, crows were trained to identify groups of dots as part of another University of Tübingen study on their counting skills. The study also captured the activity of neurons in the area of the crows’ brains responsible for processing visual inputs. The university released a statement at the time stating that the researchers discovered that the crows’ neurons “ignore the dots’ size, shape, and arrangement and only extract their number.”

“So, crows’ brains can represent different quantities, and crows can quickly learn to match Arabic numerals to those quantities –– something humans usually explicitly teach their children,” Williams said.

Last year, GreatGameIndia reported that according to a study published in the Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems, parrots have learned to video call, surpassing the hype about pigeon messengers.