“Crows ‘Count’ the Number of Self-Generated Vocalizations”, 2024-05-23 ():
Editor’s summary: Numerical ability has been increasingly identified in nonhuman animals. Animals as diverse as birds and bees have been shown to be able to “count”, and they can discriminate among different numbers of objects or between greater or fewer objects. et al 2024 tested whether crows, which are known for both their numerical skills and high level of cognition, could use vocalizations to count out loud, a skill that is challenging even for young humans. The crows flexibly produced between one and 4 vocalizations for corresponding cues associated with numerical values. Furthermore, they used different calls for different numbers.
Producing a specific number of vocalizations with purpose requires a sophisticated combination of numerical abilities and vocal control. Whether this capacity exists in animals other than humans is yet unknown.
We show that crows can flexibly produce variable numbers of 1–4 vocalizations in response to arbitrary cues associated with numerical values.
The acoustic features of the first vocalization of a sequence were predictive of the total number of vocalizations, indicating a planning process. Moreover, the acoustic features of vocal units predicted their order in the sequence and could be used to read out counting errors during vocal production.