Birds plan treats for the future
Birds can plan to save tasty food for the future and do it in a way that shows they truly plan ahead, UK researchers report.
They set up an experiment to allow the scrub jays hide food in a certain way if they are indeed planning, and found the birds were up to the task.
Their study, published today in the journal Nature, adds to several others that show animals such as great apes and certain birds can plan ahead in much the same way as people.
"Knowledge of and planning for the future is a complex skill that is considered by many to be uniquely human," write Professor Nicola Clayton and colleagues at the University of Cambridge.
"We show that the jays make provision for a future need, both by preferentially caching food in a place in which they have learned that they will be hungry the following morning and by differentially storing a particular food in a place in which that type of food will not be available the next morning," the researchers add.
The jays were kept in large cages with two rooms and were moved from one compartment to another depending on the time of day.
They also got different types of their favourite food: ground-up pine nuts, which they could not store, and peanuts and dog kibble, which they could.
First the researchers fed the birds on a schedule, with breakfast served in one compartment but not the other. Then they threw the birds off schedule by unexpectedly feeding them in the evening.
The birds stored more food if they got this surprise evening meal in the compartment where they usually were not fed than if they got the night treat in the 'breakfast room', Clayton's team reports.
In a second experiment, the birds got breakfast in both rooms but peanuts only in one and dog kibble only in the other. Then they got a chance to hide both types of food anywhere they liked.
They hid dog food in the peanut compartment and vice versa, the researchers saw.
"The results described here suggest that the jays can spontaneously plan for tomorrow without reference to their current motivational state, thereby challenging the idea that this is a uniquely human ability," Clayton's team argues.
Professor Sara Shettleworth of the University of Toronto in Canada agrees.
"Two requirements for genuine future planning are that the behaviour involved should be a novel action, or combination of actions (thus ruling out migrating and hibernating), and that it should be appropriate to a motivational state other than the one the animal is in at that moment," she writes in a commentary in the same issue of the journal.
So the animals must not be acting out of immediate hunger, for instance.
She says Clayton's experiment is the first to unambiguously fulfil both requirements.
Birds hide their food
Last May, a team led by Dr Joanna Dally of the University of Cambridge reported that scrub jays remembered which other birds were watching them when they first hid some treats. They then changed the hiding places if there was a chance the other birds could steal the food.
Jays are members of a group of birds called corvids, which include crows, jays and ravens. Biologists consider them to be the most intelligent birds.
Also last May, German researchers from the Max Planck Institute for Evolutionary Anthropology found that bonobos, close relatives of chimpanzees, and orangutans could plan and use tools.