Human-like, population-level specialization in the manufacture of pandanustools by New Caledonian crows Corvus moneduloides

The main way of gaining insight into the behaviour and neurological faculti es of our early ancestors is to study artefactual evidence for the making a nd use of tools, but this places severe constraints on what knowledge can b e obtained. New Caledonian crows, however, offer a potential analogous mode l system for learning about these difficult-to-establish aspects of prehist oric humans. I found new evidence of human-like specialization in crows' ma nufacture of hook tools from pandanus leaves: functional lateralization or 'handedness' and the shaping of these tools to a rule system. These populat ion-level features are unprecedented in the tool behaviour of free-living n on-humans and provide the first demonstration that a population bias for ha ndedness in tool-making and the shaping of tools to rule systems are not co ncomitant with symbolic thought and language. It is unknown how crows obtai n their tool behaviour. Nevertheless, at the least they can be studied in o rder to learn about the neuropsychology associated with early specialized a nd/or advanced population features in tool-making such as hook use, handedn ess and the shaping of tools to rule systems.