Nicky Clayton is no better at sitting still than are the birds she studies. Back in the 1990s, her colleagues at the University of California at Davis would stay at their computers at lunchtime, but she would wander outside and watch as western scrub-jays stole bits of students’ meals and secretively cached the food. During these informal field studies, Clayton, an experimental psychologist, noticed that the birds returned frequently to their stashes and changed their hiding places.
“I thought, ‘This is odd,’” she says. “I assumed birds would cache for a long time—days or months. But this was for minutes.” She theorized that the birds were moving their caches to avoid pilfering. When food was plentiful, they grabbed as much as possible and hid it, then hid it again when they could do so without being observed by potential thieves. That behavior implied that the scrub-jays might be thinking about other birds’ potential actions, a type of flexible thinking that was supposedly beyond the capabilities of a scrub-jay’s little brain.
Clayton realized that if she could capture this caching behavior in the laboratory, she might be able to decode the social cognition of birds—the way they think about one another. She might learn whether they are capable of deception, if they respond differently to individual competitors, how well they evaluate their degree of privacy, and other aspects of their mental processes.
“I had a lucky break with caching,” Clayton says. “I saw this as a niche, an area that other people weren’t busy with that might be quite interesting. Little did I know where it would lead.”
Scientists had already established the amazing memories of corvids, the family of birds that includes jays, crows, ravens, and nutcrackers. The Clark’s nutcracker can hide thousands of seeds at a time and has passed tests of recall up to 285 days later. Clayton sought to find out how deep those skills run. Many animals have impressive mental capabilities for certain narrow tasks, but such aptitudes seem to reflect hardwired or conditioned adaptations to specific challenges. That is distinctly different from a human’s ability to create and manipulate a flexible mental model of the world.
