Pigeons, Like Monkeys, Can Order Numbers

New research shows that pigeons can count.
Pigeons, Like Monkeys, Can Order Numbers
New research shows that pigeons can count. (Stephanie Lam/The Epoch Times)
12/26/2011
Updated:
10/1/2015
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Putting numbers into ascending order is a cognitive ability generally believed to be unique to humans and primates. According to a new study, however, pigeons can learn the numerical rules involved too.

Following the protocols of a pivotal 1998 study from Columbia University in which psychologists Elizabeth Brannon and Herbert Terrace tested rhesus monkeys on their ability to understand the concept of ordinal scales, researchers from the University of Otago in New Zealand found that pigeons can do just as well.

In the new experiment, Damian Scarf, Harlene Hayne, and Michael Colombo trained pigeons to arrange images based on their numerosities, that is, the number of elements depicted by each image. The birds were shown dozens of image sets, each consisting of three images ranging from one to three shapes, and rewarded whenever they arranged the images in the correct ascending order.

To assess if the pigeons simply memorized a pattern or if they actually learned the numerical rules and could reapply this knowledge, the team then presented the pigeons with pairs of images depicting any number of elements ranging from one to nine.

Regardless of whether the numerosities were familiar (one to three) or unfamiliar (four to nine), the pigeons correctly arranged the image pairs at a frequency significantly above chance.

“While this is obviously a long way away from how humans can count,” said lead-author Scarf in a press release, “it shows that an animal with a brain structured quite differently to ours is still able to perform complex mental tasks of which only humans were once thought capable.”

“[T]he results of the present experiment add to a growing body of work demonstrating that birds possess a number of abilities that were, at one point in time, considered primate unique, such as episodic memory and the use and manufacture of tools,” the researchers wrote in their study.

“Indeed, over the past two decades the intellectual status of birds has risen markedly. Our results suggest that, at least with respect to numerical competence, pigeons are on par with primates.”

The study appears in a Brevia in the Dec. 23 issue of Science.