Self-control, a trait usually considered to be specific to humans, has now been found to be present in cockatoos, according to a new study from University of Vienna.

There has been a lot of research understanding self-control in human babies. Back in the 1970s, a group of preschoolers were given the 'Stanford Marshmallow Experiment', in which the child was given a marshmallow and told that they could get another marshmallow if they waited a little longer. Such self-control is rarely seen in animals because it requires higher cognitive processes like the ability to think about future gain and controlling impulses.

For the study, researchers from University of Vienna chose to assess self-control in an Indonesian cockatoo species - the Goffin's cockatoo. The birds were asked to pick a food item and then return to the researcher after an increasing time delay. If the bird didn't eat the food item, then researchers rewarded it with a second food item, mostly of a higher preference.

Researchers found that though pecan nuts were favorites among the birds, they would resist eating them to get a chance of getting cashew nut. And, it wasn't just one bird that displayed such self control, but all 14 of the test birds could wait for a better nut for up to 80 seconds, researchers said in a news release.

"While human infants or primates can hold the initial food in their hands, one should also consider that the birds were able to wait, although they had to hold the food in their beaks, directly against their taste organs while waiting. Imagine placing a cookie directly into a toddler's mouth and telling him/her, he/she will only receive a piece of chocolate if the cookie is not nibbled for over a minute," said Alice Auersperg, the manager of the Vienna Goffin Lab.

Recently, BBC reported the story of cockatoo - named Figaro - that was seen using a stick as a tool to reach nuts outside its cage. These birds aren't known to use such tools in the wild.

Birds belonging to the family Corvidae that include crows, ravens and rooks are known to possess higher intelligence

"Until recently, birds were considered to lack any self-control. When we found that corvids could wait for delayed food, we speculated which socio-ecological conditions could favor the evolution of such skills. To test our ideas we needed clever birds that are distantly related to corvids. Parrots were the obvious choice and the results on Goffins show that we are on the right track," said Thomas Bugnyar, one of the study authors.

The study is published in the journal Biology Letters.