Crows can plan how many times they call

May 24. () –

Through a behavioral experiment, a research team from the University of Tübingen observed that corvids count their vocalizations when they call.

This implies that they plan in advance: from the sound of the first song in a numerical sequence it is possible to predict how many songs the crows will make, according to this research, which has been published in Science.

Carrion crows, which belong to the group of songbirds, are not characterized by the beauty of their song but by their formidable learning capacity. For example, previous studies have shown that birds know how to count. “In addition, they have very good vocal control. They can precisely control whether they want to make a call or not,” he reports. it’s a statement Professor at the Tübingen Institute of Neurobiology Andreas Nieder, one of the authors of the work. Together with his team he conducted behavioral experiments with three carrion crows to study whether they could apply these skills in combination.

The birds were given the following task: upon seeing a selection of Arabic numerals or hearing specific sounds, they had to make one to four calls, as appropriate, and then conclude their call sequence by pecking an Enter key. “All three birds did it. They were able to count their calls in sequence,” Nieder says. The response time between the presentation of the stimulus and the emission of the first call in response was relatively long. and it got bigger the more calls were required. The duration of the delay was not affected by the nature of the stimulus, visual or auditory. “This indicates that, based on the information presented to them, crows form an abstract numerical concept that they use to plan their vocalizations before issuing calls,” explains Nieder.

This finding is reinforced by analysis of the calls of individual crows in a sequence. “Using the acoustic properties of the first call in a numerical sequence we were able to predict how many calls the crow would make.” Nieder reports. However, the crows’ behavior was not without errors. “Counting errors, such as one call too many or one less, arose because the bird lost count of the calls already made or yet to be made. produce. “We can also read these types of errors from the acoustic properties of individual calls.”

The ability to produce a voluntary number of vocalizations requires a highly developed combination of numerical competence and vocal control. “Our results show that humans are not the only ones who can do this. In principle, this also opens up sophisticated communication to crows“says Nieder.