Goffin's cockatoos, one of the smartest birds in the world, teach each other carpentry, a new study has found.

These parrot species, according to researchers at the Oxford University, can learn tool-making from each other. The team at Oxford, along with colleagues from the University of Vienna and the Max Planck Institute at Seewiesen, conducted a controlled experiment to demonstrate the tool-making abilities of Goffin's cockatoos (Cacatua goffini).

Recently, BBC reported the story of a 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. The team in the current study wondered whether other cockatoos could follow Figaro's example and start using wooden tools.

The researchers constructed an elaborate experiment to understand the tool-making behavior in these parrots. They allowed a set of cockatoos to observe Figaro, while other parrots were given false instructions about how to use tools.

Birds in the fake learning group were shown that the food moved towards Figaro without any intervention (scientists achieved this feat by using magnets to move objects).

The team then allowed all birds to gather food. The trick was that to get the food, parrots had to use makeshift wooden tools. The researchers found that birds that observed Figaro could use the sticks to reach the desired goals. However, none of the birds in the other group picked up the skill.

"This is the first controlled evidence for the social transmission of an original tool use event in any bird so far," said Stefan Weber, a student from the University of Vienna, who was involved in the data collection.

What's more, Figaro's students employed their own twist to the technique and increased the efficiency of their labors. Figaro gathers nuts by holding the stick at the end and then raking them towards the cage, using a slightly different angle at each stroke. His students, however, kept the stick on the ground and "propelled the nuts into their reach by a quick ballistic flipping movement."

"This means that although watching Figaro was necessary for their success they did not imitate his exact motor activities. Successful observers seemed to attend to the result of Figaro's interaction with the tool but developed their own strategies for reaching the same result, rather than copying his actions. This is typical of what psychologists would call emulation learning," explained Dr Alice Auersperg who led the study at the Goffin Lab at the University of Vienna.

The study is published in the journal Proceedings of the Royal Society B.

A related study had earlier shown that Goffin's cockatoos display self control, a trait that was considered to be uniquely human. Birds belonging to the family Corvidae that include crows, ravens and rooks are known to possess higher intelligence.