ROOKS appear to have a better understanding of how gravity works than do chimps and babies under 6 months old.
A common way of finding out whether animals and babies understand complex concepts is to show them images of impossible events. The rationale is that viewers spend longer looking at those which defy their expectations, presumably as they try to work out what鈥檚 going on.
Chris Bird of the University of Cambridge and Nathan Emery of Queen Mary, University of London, showed rooks computer-generated images, half of which were impossible according to the laws of gravity, such as an egg floating in mid-air above a table. Almost without exception, the rooks spent more time looking at the 鈥渋mpossible鈥� images than the possible ones. They also took more second glances (Proceedings of Royal Society B, ).
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The responses were the same when the 鈥渇amiliar鈥� egg shape was replaced by a cork, proving the birds鈥� insight applied equally to any object, familiar or not.
The researchers say the result is consistent with rooks being able to solve complex problems from knowledge of cause and effect, rather than by trial and error.