There once was a brainy duckling. It could remember whether shapes or colours it saw just after hatching were the same as or different to each other.

The feat surprised the researchers, who were initially sceptical about whether the ducklings could grasp such complex concepts as “same” and “different”.

The fact that they could suggests the ability to think in an abstract way may be far more common in nature than expected, and not just restricted to humans and a handful of animals with big brains.

“We were completely surprised,” says Alex Kacelnik at the University of Oxford, who conducted the experiment along with his colleague Antone Martinho III.


Kacelnik and Martinho reasoned that ducklings might be able to grasp patterns relating to shape or colour as part of the array of sensory information they absorb soon after hatching. Doing so would allow them to recognise their mothers and siblings and distinguish them from all others – abilities vital for survival.

In ducklings, goslings and other species that depend for survival on following their mothers, newborns learn quickly – a process called filial imprinting.

Kacelnik wondered whether this would enable them to be tricked soon after hatching into “following” objects or colours instead of their natural mother, and recognising those same patterns in future.

Following patterns

To find out, they hatched the ducklings in the dark and then placed them individually in lit enclosures, with objects circling around them. At first, they tried this with pairs of solid objects that were either identical – such as a couple of prisms – or non-identical, such as a prism and a sphere.

After putting the ducklings back in the dark following this “priming” period, they returned them to the enclosure but this time offered them a choice of what to follow – either two identical objects, or two that were different.

To their amazement, they found that the birds usually opted to trail the combination they had been primed with, even if the actual shapes of the objects were different from the original ones. The ducklings might follow two identical spheres after being primed with two identical pyramids, for example.

Next, they tried it with pairs of identical objects that had either matching or different colours. The result was the same.

Of the 113 ducklings used in the experiment, 77 trailed the colour or shape pairing that corresponded to the combination of “same” or “different” they were primed with, rather than following the exact original colours or shapes. “Then we knew we were on to something,” says Kacelnik.

Is that you mum? Antone Martinho

“This remarkable research demonstrates that baby ducklings spontaneously notice abstract relationships in the world around them,” says Elizabeth Brannon at the University of Pennsylvania in Philadelphia. “Most people are aware that a baby duck will imprint on a random object – that is, they will follow it around as if it were their mother – but this shows that they can actually imprint on a concept as well, and without any training.”

Kacelnik doubts whether it would be possible to engender abstract thought in older ducklings and ducks, given that the motivation to grasp the information is instinctive after hatching. “Logic dictates it would be more difficult after filial imprinting is complete,” he says.

“It’s beautiful, careful and elegant work,” says Claudia Uller at Kingston University London. “The researchers have made use of the imprinting phenomenon to show animals do ‘think’ abstractly about objects in the world.”

She adds: “I’m a firm believer – and there’s plenty of evidence to support it – that animals process information at a level we’ve underestimated”.

Nicky Clayton at the University of Cambridge, UK, says the study shows that young chicks are capable of abstract relational thought: “The fact that young chicks can do this suggests this ability is more widespread across the animal kingdom than previously thought, and emerges earlier in development than expected.”

Journal reference: Science, DOI: 10.1126/science.aaf4247

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