Science Daily: Crows Can Use 'Up To Three Tools' In Correct Sequence Without Training.
ScienceDaily (Aug. 6, 2009) — 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.
Sequential tool use has often been interpreted as evidence for advanced cognitive abilities, such as planning and analogical reasoning, but this has never been explicitly examined.
The researchers set out to investigate what the crows really understood about the tasks and their own actions with tools. A report of their research appears in the journal PLoS One.