Primates count

Around 60 million years ago, small, lemur-like primates had evolved in many areas of the world, and 30 million years ago, primates with monkeylike characteristics existed. Could such creatures count? The meaning of counting by animals is a highly contentious issue among animal behavior experts. However, many scholars suggest that animals have some sense of number. H. kalmus writes in his nature article "Animals as mathematicians": There is now little doubt that some animals such as squirrels or parrots can be trained to count... Counting faculties have been reported in squirrels, rats, and for pollinating insects. Some of these animals and others can distinguish numbers in otherwise similar visual patterns, while others can be trained to recognize and even to reproduce sequences of acoustic signals. A few can even be trained to recognize and even to reproduce sequences of acoustic signals. A few can even be trained to tap out the number of the elements (dots) in a visual pattern... The lack of the spoken numeral and the written symbol makes many people reluctant to accept animals as mathematicians. Rats have been shown to "count" by performing an activity the correct number of times in exchange for a reward. Chimpanzees can press numbers on a computer that match numbers of bananas in a box. Gesture Matsuzawa of the primate research institute at Kyoto university in Japan taught a chimpanzee to identify numbers from 1 to 6 by pressing the appropriate computer key when she was shown a certain number of objects on the computer screen. Michael Beran, a research scientist at Georgia state university in Atlanta, Georgia, trained chimps to use a computer screen and joystick. The screen flashed a numeral and then a series of dots, and the chimps had to match the two. One chimp learned numerals 1 to 7, while another managed to count to 6. When the chimps were tested again after a gap of three years, both chimps were able to match numbers, but with double the error rate.