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Maybe “birdbrained” isn’t an insult after all –– crows, the ubiquitous urban bird, can count up to four vocally, according to the latest research.
Inquisitive creatures can not only count, but can match the number of calls they make when shown a number, according to a new study, led by a team of researchers at the animal physiology laboratory of the University of Tübingen in Germany.
The way the birds recognize and respond to numbers is similar to a process that humans use, to learn how to count as small children and quickly recognize how many objects we are looking at. The findings, published Thursday in the journal Science, deepen our growing understanding of crow intelligence.
“Humans do not have a monopoly on skills like numerical thinking, abstraction, tool making, and forward planning,” animal cognition expert Heather Williams said via email. “Nobody 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 is not limited to crows. Chimpanzees are taught to count in numerical order and understand the value of numbers, like young children. When trying to attract mates, some male frogs count the number of calls from competing males to match or even increase that number when it is a female’s turn to call. Scientists have even theorized that ants retrace their paths back to their colonies by counting their steps, although the method is not always accurate.
What this latest study has shown is that crows, like young people, can learn to associate numbers with values –– and count out loud accordingly.
Can crows count much like toddlers do?
The research was inspired by young children learning to count, said study lead author Diana Liao, a neurobiologist and senior researcher at the Tübingen laboratory. Children use number words to count the number of objects in front of them: If they see three toys in front of them, they might count as “one, two, three ” or “one, one, one.”
Perhaps crows could do the same, thought Liao. She was also inspired by a June 2005 study of chickadees adapting their alarm calls to the size of a predator. The larger the predator’s wingspan or body length, the less “dee” the chicks used in their alarm call, the study found. The opposite was true for smaller predators –– the songbirds would use more “dee” sounds if they encountered a smaller bird, potentially posing greater threats to chickadees because they more fit, said Liao.
The authors of the chickadee study could not confirm whether the little singers had control over the number of sounds they made or whether the number of sounds was an involuntary response. But the possibility might pique Liao’s curiosity — could crows, whose intelligence has been well-documented by decades of research, show control over their ability to produce a certain number of sounds, effectively “counting” as they do young children?
The crows decided to fill the cake
Liao and her colleagues trained three carrion crows, a European species closely related to the American crow, over more than 160 sessions. During the training, the birds had to learn associations between a series of visual and auditory cues from 1 to 4 and produce the same number of cases. In the example provided by the researchers, a visual appearance might be like a bright blue number, and the corresponding sound might be the second song of a drumroll.
The crows were expected to make the same number of turns as the number represented by the cue –– three chiles for the cue with the number 3 –– within 10 seconds of seeing and hearing the left. When the birds stopped counting and catching, they would tap an “Enter” key on the touch screen that would show their prompts to confirm they were done. If the birds were counted correctly, they would receive mercy.
It seemed that as the cues continued, the crows took longer to respond to each cue. Their response times increased as “more speech was forthcoming,” Liao wrote, suggesting that the crows planned the number of calls they were going to make before they opened their beaks.
The researchers could even tell how many calls the birds intended to make by the way their first call sounded –– subtle acoustic differences that showed the crows knew how many numbers they had looking at them and had the synthetic intelligence.
“They understand abstract numbers … and plan ahead as they match their behavior to that number,” Williams said.
Even the mistakes made by the crows were a little advanced: If the crows had hit one too many times, pressed the same number or submitted their answers with their beaks prematurely, Liao could and its researchers to detect from the sound of the first call where they went. wrong These are the “same types of errors that people make,” Williams said.
We are still learning how smart crows are
Birds and many other animals were previously thought to only make on-the-spot decisions based on stimuli in their immediate environment, a theory popularized by BF Skinner on animal behavior in the 20th century. But the latest research by Liao and her colleagues provides more evidence of crows’ ability to synthesize numbers to produce sound and suggests that the skill is under their control.
The study team’s findings are very specific but still significant — they challenge the now-common belief that they are simply stimulus-response machines, said Kevin McGowan, a researcher at the Cornell Lab of Ornithology in Ithaca, New York, who he spent more. than twenty years studying wild crows in their habitats. McGowan was not involved in the study.
The study, McGowan told CNN, showed that “crows aren’t simple mindless machines out there responding to their environment –– they’re thinking ahead and have the ability to communicate in a structured, pre-planned way. It is a necessary precursor to having a language.”
Crow intelligence has been studied for many years. Scientists have explored New Caledonia’s crows creating their own compound tools to find food. The birds seem to establish rules, according to a November 2013 study by Tübingen University laboratory lead researcher Andreas Nieder. The beaver’s language has puzzled scientists for years, too, with its widely varying tones and expressions, McGowan said.
The study by Liao and her colleagues is not even the first to consider whether crows can be counted. That research began with Nicholas Thompson in 1968, noted animal cognitive expert Irene Pepperberg. A research professor of psychological and brain sciences at Boston University, Pepperberg is best known for her work with an African gray parrot named Alex.
Thompson suggested that crows could be counted based on their cage, duration and number that the birds seemed to control in a particular burst of sound. Crows’ counting abilities seem to exceed the demands of survival of those abilities,” he wrote.
Another study by the University of Tübingen on the counting ability of crows from September 2015 trained the birds to recognize groupings of dots and recorded the activity of neurons in the part of the crow’s brain that receives visual stimuli and makes sense. The researchers found that the crow’s neurons “ignore the size, shape and layout of the dots and only notice their number,” the university said in a statement at the time.
“So, crows’ brains can represent different quantities, and crows can quickly learn to match Arabic numerals to those quantities — something that humans explicitly teach their children,” Williams said.
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