Parrots and cockatoos are among the most intelligent of birds; like primates, they are able to use tools, and this study showed an even higher level of intelligence.
First, the birds proved they were able to control natural impulses, abstaining from an immediately available treat in favour of receiving an even better treat after a time delay.
And a new experiment showed that the Indonesian cockatoos were willing to put in extra effort if it meant a tastier treat. If there was no reward, however, they went for the immediately available treat.
The birds were given a choice between taking a food item, or a tool which could be used to access a different food item trapped inside a box - either a stick to drag the food within reach, or a ball which could be dropped in a tube to release the snack.
The choice was between a cashew, cockatoos' preferred treat, or a less desirable pistachio. The birds seemed to consider their choices carefully and showed flexibility, responding differently to new situations, which suggests that it was not a result of learned behaviour.
For example, when offered a choice between a pecan or a tool, cockatoos chose a tool when it could be used to get a cashew, but opted for the pecan when the tool would only provide access to a pecan, or when it was the wrong kind of tool.
See the experiment in action in the video below.
The research was carried out by Isabelle Laumer, Alice Auersperg, and Thomas Bugnyar from the University of Vienna and the Veterinary University of Vienna.