Carrion crows can apply their learning ability and vocal control in combination to form an abstract numerical concept and use it for vocalizations.
Basic numerical ability (viz. capacity to understand and apply basic numerical ideas such as counting, adding etc) has been observed in animals. For example, some birds and bees show basic ability to count and discriminate between greater or lesser number of objects.
However, ability to use vocalizations to count out loud demonstrated by purposefully producing a specific number of vocalizations is a higher skill involving sophisticated combination of numerical abilities and vocal control. No animal is known to have shown this skill. Only humans have this ability. In a study published recently, behavioural scientists tested whether crows have this ability. It was found that the crows can deliberately plan how many calls to make.
Carrion crows are known to have good learning ability. They understand counting. They also have very good vocal control and can control precisely whether they want to emit a call or not. The research team designed an experiment with three carrion crows to study whether they can apply their learning ability and vocal control in combination.
The three birds were given the task of producing one to four calls as appropriate on seeing a selection of Arabic numerals or on hearing specific sounds and then conclude their call sequence by pecking on an enter key. The subject birds were able to count their calls in sequence. The response time (or the lag between presentation of the stimulus and emitting the first call in the answer was relatively long) was relatively long and became longer the more calls were required but was unaffected by the nature of the stimulus. The suggests that the crows can form an abstract numerical concept which they use to plan their vocalizations before emitting the calls. This skill is only seen in humans which makes crows the first animals other than human beings to produce a number of calls deliberately on instruction.
***
References:
- Liao, D. A., Brecht, K. F., Veit, L. & Nieder, A. Crows “count” the number of self-generated vocalizations. Science. 23 May 2024. Vol 384, Issue 6698 pp. 874-877. DOI: https://doi.org/10.1126/science.adl0984
- University of Tübingen. Press releases – Crows can deliberately plan how many calls to make. Posted 23 May 2024. Available at https://uni-tuebingen.de/en/university/news-and-publications/press-releases/press-releases/article/crows-can-deliberately-plan-how-many-calls-to-make/
***
