Monkeys can count! Researchers report a study on macaques that suggests humans may not be the only animal that can do math. From New Scientist:
(Utah State University psychologist Kerry) Jordan and colleague Elizabeth Brannon, of Duke University in Durham, North Carolina, US, trained two eight-year-old female macaques to equate beeps to dots on a computer screen. So if a monkey heard seven beeps, it knew to tap a square on the screen displaying seven dots.
Next, the researchers tested the monkeys' training in adding dots and beeps together.
The animals were presented dots of different sizes flash onto a screen. At the same time they heard a series of short tones.
To determine if the monkeys could combine the two, Jordan and Brannon showed the animals a screen with two numerical choices, represented as dots – one the correct sum, one incorrect.
Both monkeys did better than 50:50 – one added the sights and sounds correctly 72% of the time, the other 66% of the time.
Monkeys can count (New Scientist)