Bird Power

Pigeon's maths talent

Pigeons, who aren't even distant uncles to a monkey, have matched primates in a test of learning an abstract numerical concept.
Trained on one-two-three, the pigeons then had to put pairs of numbers up to nine in order, says comparative psychologist Damian Scarf of the University of Otago in New Zealand. Pigeons rivaled rhesus monkeys tested earlier at the same task, Scarf and his colleagues report in the Dec. 23 Science.
The results “suggest that despite completely different brain organization and hundreds of millions of years of evolutionary divergence, pigeons and monkeys solve this problem in a similar way,” says Elizabeth Brannon of Duke University, a coauthor of the original study of numerical order in monkeys.
Humankind may be pretty proud of its numerical prowess, but numbers four succulent fruits versus eight, one lurking lion versus three matter very much in animal life, too. Research is uncovering various kinds of number-related abilities in animals as diverse as the honeybee, mosquitofish, grey parrot, Plethodon salamanders and a waterbird called a coot.
So pigeons could be compared with other species, Scarf used Brannon's numerical-order test, which baboons and lemurs as well as some monkeys have passed. For training, pigeons saw computer screens displaying sets of three images, each with one, two or three shapes. The shapes varied so that a bird couldn't get the number order right just by pecking at increasing surface area. Scarf then rewarded birds for pecking in one-shape, two-shapes, three-shapes order.