Parrots have proved they are clever as well as pretty after using their creative bird brains to make tools from unfamiliar materials.
The Goffin's cockatoo, a native of Indonesia, is not known to use tools in the wild or to have evolved the ability to build nests from twigs.
Yet four captive birds demonstrated a striking level of lateral thinking by constructing tools to retrieve food placed out of their reach.
The hand-raised parrots, Figaro, Dolittle, Kiwi and Pipin, had to fashion a tool at least 6cm long that could be poked through a hole to dislodge a tasty piece of cashew nut.
Four materials that had to be manipulated in different ways were offered to the birds. Only one, a block of larch wood, was familiar to them. The others were leafy beech twigs, cardboard and a lump of natural beeswax.
Astonished researchers watched as the parrots tore off splinters of larch wood, trimmed twigs, and cut out appropriately sized pieces of cardboard which they used to obtain the food.
The only material none of them had any luck with was the beeswax.
Dr Alice Auersperg, who led the team at the University of Veterinary Medicine in Vienna, said: "To us, the tools made from cardboard were the most interesting ones, as this material was not pre-structured and required the birds to shape their tools more actively.
"They succeeded by placing a large number of parallel bite marks along the edge of the material like a hole punch, using their curved upper beak to cut the elongated piece out of the cardboard block after reaching a certain length."
Figaro had earlier inspired the scientists by spontaneously biting splinters from the wooden beams of his cage to manufacture tools. He used these to rake up pieces of inaccessible food.
The findings appear in the Royal Society journal Biology Letters.
