The Genius of Birds

by Jennifer Ackerman

THE AUCKLAND TEAM IS also attempting to figure out whether the crows understand basic physical principles. A “crow-appropriate paradigm” for this, as Taylor puts it, is an experimental version of the old Aesop’s fable “The Crow and the Pitcher.” In that fable, a thirsty crow comes across a half-filled jug of water. Unable to reach the water to drink, the crow drops pebble after pebble into the pitcher until the water level rises enough for him to drink. As it turns out, this is not just a folktale. New Caledonian crows will do exactly that—drop stones into a water-filled tube to raise the water level. And as Sarah Jelbert discovered while working with the Auckland team, if given a choice between heavy objects and light ones, solid and hollow ones, the crows will spontaneously pick objects that will sink over those that will float. They know how to pick their materials and will select the right option 90 percent of the time. This suggests that the crows understand water displacement, a fairly sophisticated physical concept, on par with the comprehension of a child five to seven years old. It also suggests that they’re able to grasp the basic physical properties of objects and make inferences about them.