Auersperg/SIPA/REX/Shutterstock
By Colin Barras
It’s toolmaking with intent. Goffin’s cockatoos in the lab use their beaks to carefully cut out a tool from a sheet of cardboard before using it to retrieve an out-of-reach nut.
In 2012, a male Goffin’s cockatoo named Figaro proved to be smarter than the average bird: he worked out that he could get to a nut just beyond his reach by tearing a long splinter off a chunk of wood and using it to rake the food.
The behaviour – which some other cockatoos also picked up later – seemed to suggest the intentional creation of tools with a specific design for reaching food. But there were some doubters.
“There were questions on whether the elongated shape of the tool was intentional,” says Alice Auersperg at the University of Vienna in Austria, who described Figaro’s behaviour in 2012. “He could just have bitten the material out of frustration and ended up with a functional tool due to the age lines of the wood.”
In other words, wood naturally tears into the shape of a nut-retrieving tool, making it unclear whether the birds set out deliberately to fashion tools of the right shape for the task, or whether they just stumbled upon one that works well.
Auersperg and her colleagues have now performed some follow-up investigations to make a stronger case for cockatoos having a specific intention in their toolmaking.
They worked with four male cockatoos, including Figaro. In the test runs, each bird had 10 minutes to work out how to fashion a long, thin tool from a particular object and then use the tool to retrieve a tasty cashew nut. The object they were given in different test runs consisted of a leafy twig, chunk of wood or sheet of cardboard.
All four birds quickly worked out how to strip the leaves off the twig and turn it into an effective tool. Three of the four had previously worked out how to tear long splinters off the block of wood for nut retrieval and were able to do it in this trial too. But both of these materials naturally lend themselves to forming long and thin tools perfect for nut retrieval.
Cardboard cutters
In contrast, cardboard doesn’t naturally tear into long, thin shapes. Surprisingly, though, Figaro and one other male cockatoo could still fashion a perfect nut-retrieving tool using the material.
Instead of simply pulling off chunks of cardboard at random, both birds used their sharp beaks to make a series of perforations in the cardboard sheet that created the shape of a long and thin prodding tool. They could then easily detach it from the sheet and use it to retrieve the nut.
Auersperg says the test with the cardboard makes a stronger case that the birds can “see” a useful tool in a piece of material and then set about making it.
The fact that Goffin’s cockatoos are not known to use tools in the wild makes this behaviour even more impressive.
In 2002, a New Caledonian crow called Betty became a worldwide sensation for her ability to bend a piece of wire into a hook to retrieve an inaccessible reward. This seemed to make her some sort of animal genius. Earlier this year, though, a team led by Christian Rutz at the University of St Andrews, UK, found evidence that New Caledonian crows do, in fact, occasionally fashion similar bent tools in the wild.
Rutz says careful study of birds in the wild might show that Goffin’s cockatoos are natural toolmakers too – although Figaro and his friends may have worked out how to make tools spontaneously. “Both of the options remain a possibility,” he says.
Journal reference: Biology Letters, DOI: 10.1098/rsbl.2016.0689
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