Crows Can 'Count' Out Loud, Study Shows

An anonymous reader quotes a report from ScienceAlert: A team of scientists has shown that crows can 'count' out loud -- producing a specific and deliberate number of caws in response to visual and auditory cues. While other animals such as honeybees have shown an ability to understand numbers, this specific manifestation of numeric literacy has not yet been observed in any other non-human species. "Producing a specific number of vocalizations with purpose requires a sophisticated combination of numerical abilities and vocal control," writes the team of researchers led by neuroscientist Diana Liao of the University of Tubingen in Germany. "Whether this capacity exists in animals other than humans is yet unknown. We show that crows can flexibly produce variable numbers of one to four vocalizations in response to arbitrary cues associated with numerical values." The ability to count aloud is distinct from understanding numbers. It requires not only that understanding, but purposeful vocal control with the aim of communication. Humans are known to use speech to count numbers and communicate quantities, an ability taught young. [...] "Our results demonstrate that crows can flexibly and deliberately produce an instructed number of vocalizations by using the 'approximate number system', a non-symbolic number estimation system shared by humans and animals," the researchers write in their paper. "This competency in crows also mirrors toddlers' enumeration skills before they learn to understand cardinal number words and may therefore constitute an evolutionary precursor of true counting where numbers are part of a combinatorial symbol system." The findings have been published in the journal Science.

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