Rooks Use Tools The Return: More From The Clever Corvids

A previous blog post about how rooks are capable of using tools to get to food has a follow up. In the previous experiment the birds fashioned hooks out of wire to pull up a tray containing food. The latest adventures show that they understand the displacement of water and use stones to get a drink, even so far as to realise that larger stones will displace more water and so get the drink faster. Aesop's fable about the crows using stones may have been based on fact after all suggests the BBC.