The strongest evidence yet that animals plan ahead may come from western scrub jays preparing for their morning meals.
Plenty of animals perform actions that bring future benefits, but those activities don’t necessarily demonstrate planning, says Nicola S. Clayton of the University of Cambridge in England. Smart moves may be just responses to cues, either innate or learned. Geese don’t necessarily plan when they fly south as winter approaches. And a cat may have learned that the sound of a car in the driveway means food will soon appear in its bowl.
Researchers cite planning only when an animal acts to satisfy a future need that’s different from its current one. A cat lurking by a mouse hole is already hunting, not planning for a future hunt.
Now, though, Clayton and her colleagues say that they’ve found scrub jay behavior that qualifies as planning. In a lab setup, scrub jays cache food in places where they have previously been stuck without any breakfast. The birds also cache particular kinds of food in places that hadn’t provided them, Clayton and her colleagues report in the Feb. 22 Nature.
The jay results are the first in any animal that “unambiguously” meet the criteria for planning, comments comparative psychologist Sara Shettleworth of the University of Toronto.
In the wild or the lab, scrub jays bury nuts (SN: 5/20/06, p. 309: Jay Watch: Birds get sneakier when spies lurk). To prepare the birds for the test, Clayton and her colleagues housed jays in suites with two annexes. Researchers pulverized food provided to the jays during this initial phase to prevent them from caching it. 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, which had food available. Thus, the birds had information about where food would be available in the mornings.
For the test, researchers served whole pine nuts to the jays on a single evening. The birds could eat their fill of the nuts and still cache extras in either annex. The eight scrub jays in the test deposited most of their cache in the no-breakfast annex.
In a second experiment, Clayton and her colleagues during mornings served peanuts in one annex and kibble in the other. When the researchers offered the birds a chance to cache the foods in either place one evening, the jays put more of each food in the compartment that had lacked it. This shows that the birds planned to have the missing alternative food for a later meal, say the researchers.
This is the first test of animal planning “to make a strong case,” says Thomas Suddendorf of the University of Queensland in St. Lucia, Australia. He has been critical of earlier experiments with other animals. He does caution—and Clayton agrees—that the results don’t show whether scrub jays plan the way people do, with imaginary time travel into the future.