Western scrub-jays plan for the future, caching seeds in locations where previously they have gone hungry, according to British researchers.
Credit: Wikipedia
PARIS: Humans are not the only animals capable of planning for the future, according to a new study.
In an experiment designed by British scientists, eight western scrub-jays (Aphelocoma californica) forestalled a lack of food by stashing pine nuts the night before in a location where, during a series of two-hour morning lock-downs, they had earlier gone unfed.
The birds stocked only a third as many goodies in a second location where they had, by contrast, been allotted morning meals on alternate days during the previous week.
"The birds behaved as if they were planning for breakfast by caching food items in the place where the food was most likely to be needed," observed Sara Shettleworth, a professor of psychology and zoology at the University of Toronto in Canada, who wrote a commentary on the research in the British journal Nature, which also published the study.
To truly demonstrate the capacity to think ahead, she said, the birds needed to fulfill two criteria. They had to demonstrate a novel action, ruling out deeply ingrained behaviour such as migration and hibernation, and they had to show the capacity to anticipate a 'motivational state' - in this case, hunger - that they were not experiencing at the time: the scrub-jays had had plenty to eat when they set about stocking the larder for the morning after.
Previous research had shown that scrub-jays have a concept of the past, remembering what they have cached, where, and how long ago. Other studies have reported that they also keep track of which particular bird was watching when they cached so that they can more effectively protect their caches from being stolen.
"Knowledge of and planning for the future is a complex skill that is considered by many to be uniquely human," wrote the authors, led by Caroline Raby of the University of Cambridge. "The results described here suggest that the jays can spontaneously plan for tomorrow … thereby challenging the idea" that only humans are able to think ahead.
To further test their hypothesis, the scientists designed a second experiment similar to the first in which the birds were fed, on alternate mornings, different types of food - pine nuts and tiny dog biscuits - in two separate locations.
When they were suddenly offered both one evening, the birds "distributed their caches to provide each room with the kind of food it usually lacked," as if to insure that they would have a more varied breakfast the next day, said Shettleworth.
