 The Roman naturalist Pliny the Elder is the earliest to attest that the story reflects the behaviour of real-life corvids.In August 2009, a study published in "Current Biology" revealed that rooks, a relative of crows, do just the same as the crow in the fable when presented with a similar situation.The ethologist Nicola Clayton, also taking the fable as a starting point, found that other corvids are capable of the thinking demonstrated there.