Many birds store vast quantities of food in various hiding spots, which they later recover when food is scarce. (Clark's nutcracker, for example, is able to store more than 30,000 seeds in hundreds of hiding spots over a 12-square-mile area. No primate can match this.) The problem with stored food, however, is that it's easy to steal. As a result, many birds regularly re-hide their food if they suspect other birds have observed their original spots. This suspicious behavior depends on a very impressive feat of social intelligence, which had never before been observed outside primates. Nicola Clayton and Nathan Emery, another researcher at the University of Cambridge, showed in 2001 that only western scrub jays that had previously stolen food from other birds would always re-hide their food. Jays that had never stolen before didn't worry about being stolen from. "These birds are projecting their experience of being a thief onto other birds," Clayton says. "They are thinking 'Well, I've stolen food, so this guy might too.' It's a form of mental simulation." source: http://www.boston.com/news/globe/ideas/articles/2007/09/16/eggheads/?page=3 This is a really interesting article that should redefine your concept of the "bird brain".. in many areas, bird intelligence rivals that of primates.