Aesop's crow 'may have been real'

The crow is truly as clever a bird as legends portray it to be, new research has shown.

Scientists at Cambridge University have demonstrated that the millennia-old fable about a thirsty crow that raised the water level of a pitcher by throwing stones into it is based on the bird's innate ability.

The problem-solving ability described in the tale written by Ethiopian slave Aesop was tested by a team of zoologists on a group of rooks, birds belonging to the same corvid family as crows.

The study published in the journal Current Biology, reports how the four rooks - Cook, Fry, Connelly and Monroe - were offered a juicy worm floating on water in a vertical tube, just beyond their reach. Their behaviour was recorded on video.

To start with they appear to be thinking through the problem by examining the tube from all angles.

The researchers then place a handful of pebbles near them. The birds pick these up with their beaks, drop them in the tube and bring the worm within reach. While Cook and Fry succeed at their first try, it takes Connelly and Monroe two attempts.

Cambridge University zoologist Christopher Bird, who led the study, said: "Corvids are remarkably intelligent, and in many ways rival the great apes in their physical intelligence and ability to solve problems," said Mr Bird, a PhD student.

"This is remarkable considering their brain is so different to the great apes."

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