A Comparative Mind: Crows can ‘reason’ about causes, a recent
study finds In an experiment, researchers found that crows were
more likely to forage when they could attribute changes in their
environment to a human presence. This behaviour may suggest
“complex cognition”, according to a study published in the
Proceedings of the National Academy of Sciences. Until now the
ability to make inferences based on causes has been attributed
to humans but not animals. The study was a collaboration between
researchers from the University of Auckland, New Zealand, the
University of Cambridge, UK and the University of Vienna,
Austria. In their experiment eight wild crows used tools to
remove food from a box. Inside the enclosure there was a stick
and the crows were tested in two separate series of events that
both involved the stick moving. In one instance a human entered
the hide and the stick moved. In the other, the stick still
moved but no human entered. On the occasions when no human was
observed entering the hide, t