PERHAPS “birdbrained” isn’t such an insult after all — crows, the ubiquitous urban bird, can vocally count up to four, the latest research has found.

Not only can the inquisitive creatures count, but they can match the number of calls they make when shown a numeral, according to a new study, led by a team of researchers with the University of Tübingen’s animal physiology lab in Germany.

The way the birds recognize and react to numbers is similar to a process we humans use, both to learn to count as toddlers and quickly recognize how many objects we’re looking at. The findings, published last week in the journal Science, deepen our growing understanding of crow intelligence.

“Humans do not have a monopoly on skills such as numerical thinking, abstraction, tool manufacture, and planning ahead,” said animal cognition expert Heather Williams. “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.

In the animal kingdom, counting isn’t limited to crows. Chimpanzees have been taught to count in numerical order and understand the value of numerals, much like young children. In attempting to woo mates, some male frogs count the number of calls from competing males to match or even one-up that number when it’s their turn to croak at a female. Scientists have even theorized that ants retrace their paths back to their colonies by counting their steps, though the method isn’t always accurate.

The new research was inspired by toddlers learning to count, said lead study author Diana Liao, a neurobiologist and senior researcher at the Tübingen lab. Toddlers use the words of numbers to tally the number of objects in front of them: If they see three toys in front of them, their counting could sound like “one, two, three” or “one, one, one.”

Liao and her colleagues trained three carrion crows over more than 160 sessions. During the trainings, the birds had to learn associations between a series of visual and auditory cues from one to four and produce the corresponding number of caws.

It appeared that as the cues continued, the crows took longer to react to each cue. Their reaction times grew as “more vocalizations were impending,” Liao wrote, suggesting that the crows planned the number of caws they were going to make before they opened their beaks.

Crow intelligence has been studied for decades. Scientists have investigated New Caledonian crows creating their own compound tools to access food. The birds appear to establish rules, according to a November 2013 study coauthored by the University of Tübingen lab’s lead researcher, Andreas Nieder. Crow language has also confounded scientists for decades, too, with its widely varying tones and expressions.

(SD-Agencies)