Friday, March 02, 2007

Birds Plan their Future Menus, Scientists Say

Western Scrub Jay photo courtesy of Arizona Game & Fish Division

Researchers say that Western scrub jays are the first animals to unambiguously meet the criteria for "planning" behavior. Scientist Nicola Clayton of the University of Cambridge in England reported her observations in the Feb. 22 issue of the journal Nature. The birds in the study were seen to store food in places where they were previously stuck with nothing to eat. They also were observed to cache certain kinds of food in spots where that kind of food had not been available in the past.

In humans, planning is the result of imaginary time travel. Whether the birds were engaging in imaginary time travel can't be known for sure. But behavior that seems to result from imaginary time travel has never been reported for any animal in research journals before now.

To set up the study, Clayton and her colleagues housed the jays in suites with two annexes. On some mornings, the researchers confined a bird in one of the annexes for 2 hours with no breakfast. On other days, the researchers kept the bird in the other annex, where food was available. So the birds knew which annex had food and which didn't.

For the experiment, the researchers served whole pine nuts to the jays. The birds could eat as many as they liked and cache the rest in either annex. The 8 birds in the test cached most of their nuts in the no-breakfast annex.

In a second experiment, the researchers offered the birds peanuts in one annex and kibble in the other. The birds cached more of each food in the annex that lacked it.

The researchers say the results show that the birds planned what they would have available to eat for future meals.

Other scientists - Sara Shettleworth of the University of Toronto and Thomas Suddendorf of the University of Queensland - concur with Clayton that the results show strong evidence of planning, much more so than previous behavioral experiments.

This behavior is different from, say, a dog running to the door at the sound of a car in the driveway, which is simply a response to a conditioned stimulus. It is also different from a cat lying next to a chipmunk hole, which may seem to be planning but is actually a hunt already in progress.

This behavior is not the same as a squirrel hiding nuts, either, which can be explained as just instinctive behavior with no imaginary reflection on how satisfactory the nuts will be at a future time.

The caching by Western scrub jays does seem to show "imaginary time travel" to events that could be weeks away - events which require some menu-adjustment in order to satisfy the choosy diners.

Source: S. Milius. "Bird plans." Science News, Volume 171. February 24, 2007.

Keywords: bird behavior bird intelligence scrub jays bird research planning behavior food cache

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