The gray parrots ( Psittacus erithacus ) , which live in the middle of the African bush, are able to reason logically in a similar way to how great apes and three-year-old human children do, according to an Austrian and German study published the journal Proceedings of the Royal Society B in its latest edition.
To reach this conclusion, Judith Schmidt and her colleagues used two small opaque plastic boxes, one full of food and the other empty. By shaking the boxes, they found that the birds deduced that the jar that sounded was the one that contained the nuts. If they only shook the empty container (which did not produce any sound) they also immediately deduced that it was not the empty container but the other one that contained the food, and they went quickly towards it. In short, the gray parrots found the food with the same speed, shaking the two glasses or just one of them horizontally. Humans are not capable of this kind of logical reasoning before they are three years old .
Unlike parrots, non-ape primates achieve this ability only after undergoing intense training, scientists clarify.
