In American slang, to call someone "bird-brained" is to call them "stupid." But according to a recent study, some birds are smart enough to learn from the past, to plan for the future and to project their own habits onto other birds.
Nicola Clayton is a behavioral scientist with a special interest in non-human psychology. Her recent work has focused on the scrub jay, a bird common to the American West, which caches, or hides, its food for future use. "They rely on memory to recover their caches much in the same way as, hopefully, we use memory to keep track of where we last left our car keys," she said.
Ms. Clayton first became intriqued by the psychology of scrub-jays during outdoor breaks at the University of California at Davis, where she was working. "You'd see them come and steal bits of food from students and staff," she said. "But the birds would fly off quickly and hide their caches. But there would be lots of other birds around and you'd see them hide it very quickly. And when the other birds had all flown off, you'd see them come back and quickly recover those caches. But rather than eating them, they would rapidly rebury them after their rivals had left the scene."
So we wondered whether they were doing this to minimize the chance of their caches being stolen. So you can think of it as a case of avian espionage, with these birds, on the one hand, being very good of spying upon and stealing the caches of their neighbors, but, at the same time, being sure that their neighbors were much less likely to steal their own caches. So what we did in the laboratory was to attempt to test this hypothesis.
"We allowed the birds to cache in private or while observed by another scrub jay," she said. "But then all the birds were allowed to recover their caches in private. In that way, we were allowed to see whether the birds only did this behavior of quickly coming back and re-stashing if they had been observed."
Ms. Clayton says the results were instructive.
"We found that if they had been observed by another bird, they are much more likely to re-cache in private than if they had done their caching in peace and quiet. But it depended upon what their experience was. So one group was given the opportunity to steal other birds' caches. They were the thieves, if you like. Another group was not. And we found that the thieves did in fact [re]hide their own food caches if they had been observed when first hiding the food. But the 'innocent' ones, the ones that didn't have this thieving history, didn't exhibit the same cunning behavior of re-stashing their caches later."
Ms. Clayton and her fellow researchers drew two main conclusions from these observations. "It was claimed for many years that animals were stuck in the present, that they couldn't go back in time and re-experience the past, and they couldn't plan for the future. And the fact that these animals are able to go back in time and remember whether or not they were being observed and then use that observation to think about the future consequences of their food namely whether or not they need to re-cache them or not suggests that they may be capable of at least some rudimentary form of future planning. That being a thief themselves, they know to re-cache the food. Those that haven't been thieves don't," she said. "And the other very exciting possibility is that these scrub jays might possess sophisticated thought processes that allow them to anticipate and outwit the actions of other birds."
But don't worry. Nicola Clayton assures us that while thinking about the thinking of birds is something that humans share with scrub jays, writing and listening to radio reports about it are activities that, so far, only humans can do.