New experiments by Oxford University scientists reveal that New Caledonian crows can spontaneously use up to three tools in the correct sequence to achieve a goal, something never before observed in non-human animals without explicit training.
Betty does not attempt to probe for food, but immediately uses the tabletop tool to retrieve a medium-length tool. She then appears to look into the food-tube, without probing, before using the tool to extract the longest tool. Finally, she uses this tool to retrieve the reward from the food-tube. It is noteworthy that she seems to actively dispose of each tool as its role in the sequence is completed, and she also turns the tools around in order to place the cross-piece distal, where it is most effective as a hook-like instrument.
Published in PLoS ONE, august 5th 2009. Authors:
Joanna H. Wimpenny, Alex A. S. Weir, Lisa Clayton, Christian Rutz, Alex Kacelnik