Cockatoos are smart birds, and the Goffin’s cockatoos in a Vienna lab are among the smartest. In an experiment reported about a year ago, they turned out to be real stars at making tools from a variety of materials in order to get a treat.

In a new study, researchers tested the birds’ ability to match shapes using an apparatus reminiscent of a child’s toy. The birds had to put a square tile into a square hole and more complicated, asymmetrical shapes into matching holes. If they were successful, they got a treat.

Cornelia Habl, a master’s student at the University of Vienna, and Alice M. I. Auersperg, a researcher at the University of Veterinary Medicine in Vienna, ran several experiments. They reported in the journal PLOS One that the cockatoos were not only able to match the shapes to the holes, but did much better than monkeys or chimpanzees.

“It was thought to be an exclusively human ability for a long time,” Ms. Habl said. Tests of matching shapes are used to mark milestones in child development.