Ecologists from the University of St Andrews in the UK were able to observe and record the tool-assisted foraging behaviour among New Caledonian (NC) crows in the wild.
NC crows are the only non-human species known to create hooked tools to extract embedded prey in the wild. Little is known on how the tools are made and used due to the shy nature of these species. This study was the first to help obtain the amount of time NC crows spend foraging with and without tools.
Miniature video cameras were attached to 19 wild crows. The footage of 10 birds was recovered and analyzed after about a week.
The study published in the journal Biology Letters states: “across all 10 birds, it was estimated that tool-related behaviour occurred in 3% of total observation time, and accounted for 19% of all foraging behaviour,”
Footage from the University of St Andrews on the New Caledonian crow’s Behaviour.
The recordings revealed the birds made the hooked tool by snapping off the twig just above and below a branching node. The crow then stripped the bark and leaves from the longer, thinner branch and created a hook at the node.
This research will further help ecologists determine the reason behind this little understood behaviour of NC crows.
However, due to short recording periods, the study cannot determine if individual crows are similar in their reliance on tool-assisted foraging.
Previously observed tool use behaviour of the New Caledonian Crow in lab setting.