Birds count like people

The only non-species counts numbers from left to right, by a study proving that birds do the same.

Scientists have long discovered that many animals - like honey bees, lemurs, North American ginseng, and red-back salamanders - are capable of counting. However, no one has demonstrated that animals "read" numbers from left to right just like people.

Scientists at the University of Padua (Italy) investigate the bird's counting ability by studying a group of Clark nut-feeder birds (belonging to the crow family). This herd has both mature individuals and young offspring. The team placed many objects in a row and trained the birds so they knew how to choose the fourth object from top to bottom. Every time a bird strikes a fourth object, they receive a food reward.

Initially objects were placed vertically in front of the birds. But when they were proficient in choosing the fourth object, the experts set the objects horizontally and arranged them in order from left to right.

Clark nutcracker.Photo: nationalzoo.si.edu .

The results showed that birds still count the fourth object. That proves they know how to count from left to right.

'This is the first time we have demonstrated that counting from left to right is not a separate behavior of humans,' the team concludes in Biology Letters.

In another study of starling, scientists at the University of Chicago (USA) demonstrated that, like humans, birds remember better after deep sleep.

The team trained rock flute so that they responded to two sounds, in which a sound signaled that they would receive food and another sound signaled they would be punished. After a sleep flock the bird distinguishes two sounds easier than when they don't sleep.

The University of Chicago study is published in the journal Neuroscience.