EVIDENCE THAT GOFFIN’S cockatoos (Cacatua goffiniana) can construct the same tool out of different materials to reach food has been highlighted in a new study.
These native Indonesian birds are not known for using tools in the wild, but scientists from the University of Veterinary Medicine in Vienna and University of Oxford built on previous research of four Goffin’s cockatoos spontaneously manipulating twigs into tools and using them to rake food out of reach.
In the new study, four hand-raised adult males were offered the problem of reaching a piece of cashew nut placed a few centimetres beyond a circular hole in a transparent box using larch wood, cardboard, leafy beech twigs and amorphous beeswax.
Three had previously sculpted tools out of larch wood; one had also manufactured a tool by removing a side branch from a bamboo twig; and another had used but not made tools before.
Co-author Professor Alex Kacelnik explained: “Studying tool-making in species like the Goffin’s cockatoo, which does not make tools naturally, is especially revealing, as these birds cannot do it by following pre-programmed instructions evolved to solve this specific problem.
“We really don’t know if the birds can picture in their minds an object that doesn’t yet exist and follow this image as a template to build something new, or how their brains elicit the appropriate set of movements to organise their response to novel problems, but this is what we are trying to find out.”
All four made well-shaped tools, even though each material required a different technique.
To make tools from larch wood, the birds bit the material once or twice and tore off the resulting splinter. With the leafy twigs, they snapped off redundant leaves and side branches until what was left was usable. And to make cardboard tools, the cockatoos cut what was necessary from the edge of the sheet provided. None were successful with beeswax.
Dr Alice Auersperg added: “To us, the tools made from cardboard were the most interesting, as this material was not pre-structured and required the birds to shape their tools more actively.”
The study was published in the journal Biology Letters.
Photo: Bene Croy