Pigeons as smart as monkeys: Study

This is stunning because it's trait that has only been shown in primates. Past studies have shown that various animals, from honeybees to chimpanzees, can learn to count when trained with food rewards.

In the new study, published in the journal Science, the researchers were also able to teach pigeons abstract rules about mathematics.

"Pigeons are the perfect subjects for visual tasks, because their vision is really good and they're really easy to train," Damian Scarf, first author of the study, was quoted as saying by LiveScience.

"It appears that you can train them on almost any task you can train monkeys on."
For their study, Scarf and his colleagues first trained three pigeons to count up to three. On a touchscreen, they presented the pigeons with a set of images that had objects of various sizes, shapes and colours.

For example, one set presented images with one yellow block, two red cylinders or three yellow rectangles. To receive a treat, the pigeons had to select the images in the correct object-number order, from lowest to highest.

Once the birds learned to count to three, the researchers began showing the pigeons images with up to nine objects. On average, without higher-number training or food rewards, the pigeons were able to correctly order the image sets over 70 percent of the time.

The pigeons had an easier time discriminating between lower numbers and numbers that were further apart.

"Once you start getting up towards seven, eight and nine, it was very difficult for [the pigeons] to tell the difference between the images," Scarf said.
Overall, the results of the study echoed those of the rhesus monkey research, though Scarf noted it took longer to train the pigeons than other researchers took training monkeys, he added.