Fascinating article in the New Scientist about potential theory of mind in members of the crow family. Theory of mind (wikipedia), as you know, is the ability of one being to estimate what another being might be thinking or how he might respond to a given situation. For instance, I can imagine that my husband would want some strawberry shortcake if it were available, or that he would be excited if the Jets went to the Superbowl next year. Children as young as 3-4 years of age have some understanding that others have thoughts different from their own, but generally animals and birds are not thought to have this ability.
Research by Joanna Dally, associated with the Comparative Cognition Lab at Cambridge, writes about some interesting developments in crow and scrub-jay behavior that point to potential awareness of how other birds might respond to their actions. Nicky Clayton and Nathan Emery studied food-hiding and stealing habits of scrub-jays:
"The allowed jays to hide worms either while they were alone or when another bird was watching, and to recover the hidden items in private later that day. Worms are the 'Belgian truffles' of the jay's gastronomic world, so the researchers anticipated that birds would make every effort to protect their stores. They found that when jays were allowed to return to their stash, those that had hidden worms under the gaze of a would-be thief moved them to new sites. Birds did not move worms they had hidden in private, however."
Further research carried out by Dally and Clayton showed that this was not the only strategy jays use to protect their worms: "we found that when hiding worms with another bird around, jays prefer to cache their meal behind a barrier that blocks their rival's view. That might not sound very clever," Dally continues, "but it suggests they may be able to see things from the visual perspective of another individual. In other words, they might understand that another bird learns about the world through its sense of vision" (emphasis mine).
Further research includes suggestions that jays are aware of what other birds know and when they know it (jays are more likely to re-hide food when they know that someone watched them hide it in the first place). Also, jays who have never stolen worms themselves are less likely to re-hide worms.
Fascinating suggestions about the intelligence of scrub-jays, and by extension, the crow family. Bird brains are notoriously small, but these jays are pretty smart about what other birds know about their food.
For More Information
* Dally, Joanna. "Don't Call Me Birdbrained." The New Scientist, 194.2609, 23 (2007): 34-37. [will be available on InfoTrac in a few weeks; now available in LexisNexis]
* Dally, Joanna, Nathan Emery, and Nicola Clayton. "Cache Protection Strategies by Western Scrub-Jays, Aphelocoma Californica: Implications for Social Cognition." Animal Behaviour 70.6 (2005): 1251-63.
* Emery, Nathan and Nicola Clayton, "Effects of Experience and Social Context on Prospective Caching Strategies by Scrub Jays." Nature, 414.6862 (2001): 443-446.
* Animal Consciousness, Stanford Encyclopedia of Philosophy, 2006.