Crows can not only count but also match the number of their calls to a numeral they see, according to a new study by researchers at the University of Tübingen in Germany.
These birds recognize and respond to numbers in a way similar to how humans learn to count and quickly identify quantities. The findings, published in the journal Science, show just how intelligent crows are.
“Humans do not have a monopoly on skills such as numerical thinking, abstraction, tool manufacture, and planning ahead,” said Heather Williams, an animal cognition expert and biology professor at Williams College, who was not involved in the study. “No one should be surprised that crows are ‘smart.’”
Counting is not unique to crows in the animal world. Chimpanzees can count in order and understand numeral values like children do. Male frogs count the calls of rivals to outdo them when attracting females. Some scientists even believe ants count their steps to find their way back to their colonies, although this method isn’t always accurate.
This latest study shows that crows, like young humans, can learn to associate numerals with values and count out loud accordingly.
Do crows count similar to toddlers?
The idea for the research came from watching how toddlers learn to count, explained Diana Liao, the main scientist behind the study and a senior researcher at the Tübingen lab. When toddlers see objects, they use number words to count them.
For example, if there are three toys, they might count, “one, two, three” or “one, one, one.” Liao wondered if crows could do something similar.
She was also inspired by a study from June 2005 about chickadees adjusting their alarm calls based on the size of predators. The study found that when faced with larger predators, chickadees made fewer “dee” sounds in their alarm calls.
However, when dealing with smaller predators, they used more “dee” sounds, as these could be bigger threats to chickadees due to their agility.
The researchers of the chickadee study weren’t sure if the birds could control the number of sounds they made or if it was just a reflex. But this got Liao thinking: could crows, known for their intelligence from many studies, have control over how many sounds they make, similar to how toddlers count?
The crows carefully decided their number of caws
Liao and her friends taught three carrion crows, birds similar to American crows, in more than 160 sessions. In these sessions, the birds had to learn connections between what they saw and heard and how many times they needed to caw. For example, if they saw a bright blue number 3, they had to make three caws after hearing a short drumroll sound.
The crows had to make the same number of caws as the number shown on the cue, like three caws for the number 3, within 10 seconds. After they finished counting and cawing, they would peck a button on a screen to say they were done. If they got the count right, they got a treat.
As the cues kept coming, the crows took longer to respond to each one. Their reaction times got longer as they knew they had more caws to make, suggesting they planned how many caws to make before they started cawing.
The researchers discovered something amazing about crows—they can understand numbers! Not only that, but they can also plan ahead based on the numbers they see.
For example, if a crow saw the number 3, it knew it had to make three caws. And get this—even if the crow made a mistake, like cawing too many times or getting confused, the researchers could figure out what went wrong just by listening to the first caw. It’s kind of like when humans make mistakes.
We’re still uncovering Crow’s Intelligence
In the past, it was believed that animals, like birds, only reacted to what was happening around them without much thought. This idea was made popular by a scientist named B.F. Skinner in the 20th century.
However recent research by Liao and her team suggests that crows might be smarter than we thought. They found that crows can understand numbers and use them to make sounds.
Kevin McGowan, a researcher at Cornell Lab of Ornithology, who has studied crows for over twenty years, says this research is important. It challenges the old idea that animals simply react to their surroundings without thinking. McGowan wasn’t part of the study.
McGowan explains that the study shows crows aren’t just reacting to what’s happening around them. They’re actually planning ahead and communicating in a structured way. This is an important step towards understanding how language might develop in animals like crows.
Exploring Crow’s Intelligence
For many years, scientists have been studying how smart crows are. They’ve watched New Caledonian crows make tools to get food, showing that they follow certain rules, as found in a study from November 2013 by researchers at the University of Tübingen, led by Andreas Nieder.
Understanding the crow language has also puzzled scientists. Kevin McGowan, who has been studying crows for a long time, says their sounds and expressions vary a lot, making it hard to understand.
The recent study by Liao and her team isn’t the first to look into whether crows can count. Back in 1968, Nicholas Thompson started this research. Irene Pepperberg, an expert in animal thinking from Boston University, mentioned this. Pepperberg is famous for her work with a parrot called Alex.
