The ontogeny of vocal identity in carrion crows (Corvus corone)

For social species, the ability to identify individual group members is crucial. Vocalizations often carry individual signatures that can serve as cues for the caller's identity. However, it is still unclear how consistent these signatures are and how early they develop. Here, we investigate the development of vocal individuality in hand-raised carrion crows. Over the course of four weeks, spanning both the nestling and fledgling stage, we recorded vocalisations of known individuals across various behavioural contexts. We show that vocal individuality is present early on and is encoded by several acoustic parameters whose importance remains consistent as the birds age. Additionally, while vocal dissimilarity between individuals generally increased over time, the pattern of change varied across contexts. Our findings highlight the dynamic nature of vocal individuality coding during early life and provide new insights into the relationship between vocal and social development in corvids.