Toddlers love fitting shapes to frames (circle to circle, cloverleaf to cloverleaf) and primates aren’t bad at it, but Goffin’s cockatoos turn out to make monkeys look thick. Their achievement despite not having hands may cause science to rethink the evolution of tool use.
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Aligning an object not just to one’s body but in relation to a surface with a specific shape requires use of landmarks rather than the own body as a frame of reference for orientation. The ability to do so is considered important in the development of tool use.
The bird-brains learned to select the right shapes for the forms faster than monkeys, say Cornelia Habl and Alice Auersperg from the University of Vienna and the University of Veterinary Medicine Vienna, reporting in PLOS One.
The plumed parrots are not habitual tool users, which could have explained their shape-frame matching abilities. They are apparently really smart, love to play, and get easily bored, by the way. Moreover, while they may not have thumbs, their tongues are highly dexterous.
There are simple moves like fitting a circle into a circle. Then there are non-symmetrical objects, which can only have one possible orientation. That’s where the birds – 13 adults were used in this experiment – really shone.
Human babies can do the circle trick from about one year of age; cube insertion starts at two. Only by three or even four do the kids start rotating objects and comparing them with the shape before insertion – and primates can’t do that, not even the apes. Despite their dexterity they can only fit simple shapes into corresponding frames and require many placement attempts, say the scientists.
The birds demonstrated their smarts using a box with an exchangeable, transparent front that had a shaped hole at its center. When the bird pushed the right object through the aperture, it got a nut. And they selected the correctly shaped objects from up to five different shapes almost immediately without requiring any training, attests Habl.
That’s not all. “They required fewer placement attempts to align simple shapes (circle, square, triangle) than non-human primates,” she says.
Goffin’s cockatoos also turn out to be efficiency hounds. “They turned complex object shapes in a way that would minimize their effort during insertion. For example, a cross-shaped object would be turned at 90 degrees, so only two protrusions would have to be inserted instead of four,” Habl says.
The long and short is that despite lacking hands, the cockatoos required fewer placement attempts than primates to insert simple object shapes into corresponding grooves, according to Habl and Auersperg. “For complex shapes, they reduced their insertion effort by rotating shapes in their beak while avoiding as many protrusions as possible,” they wrote. While they don’t habitually make and use tools, the cockatoos are adept foragers, and this ability could be helpful.
What do we learn from all this? Aligning an object relative to a surface with a specific shape requires using landmarks, rather than one’s own body, as a frame of reference for orientation. This ability to recognize orientation and shapes is considered key to the development of tool use.
A lot of species, from crows to chimps, but not cockatoos, are known for tool use. Yet these cockatoos thumbed their beaks at the prevailing wisdom and selected the correct shapes “above chance level” from early on in the experiment. Griffin’s cockatoos aren’t about to take your keys and steal your car for a joyride, but that may be because they’re too small to see over the driving wheel.