Opportunistic Tool Use by Two Unexpected Corvid Species.

This Nature note reports the first documented instance of tool use in Sunda crows () and provides additional evidence of this ability in house crows (). At Singapore Zoo (December 2023), individuals from both species spontaneously manipulated a hooked stick to extract food rewards from enclosed containers. This observation extends the catalogue of tool-using corvids. We briefly review tool use across the corvid family and examine competing hypotheses regarding its evolution, including inherited predisposition from a tool-using ancestor and the development of general physical intelligence with food caching as a potential precursor. Our findings suggest that the cognitive foundation for tool use may be conserved across the corvid family, with expression contingent upon environmental demands rather than species-specific adaptations. This work contributes to ongoing discussions regarding the evolutionary origins of complex problem-solving in birds and the potential role of general physical intelligence in corvid cognition.