There’s no doubt that corvids - the family of birds that includes crows, ravens, jays and magpies - are smart. But as Ed Yong at The Atlantic reports , a new study on ravens shows just how intelligent the birds are. Researchers found they can actually delay gratification and plan for the future - a skill only previously documented great apes and in humans age four and older.
London University researcher Mathias Osvath raised five ravens for this study at his farm in Sweden. According to Yong, Osvath and his colleagues set up an experiment in which they trained the birds to open a puzzle box by dropping an oblong stone into a tube, which unlocked a box of tasty dog kibble. The researchers then moved the puzzle box out of the bird's sight. An hour later, they offered the birds a tray covered with enticing objects, including the stone that opens the puzzle box.
Though the birds had no knowledge of whether the kibble box would return or not, the ravens chose the box-unlocking stone from the tray in 86 percent of the tests. In a similar experiment, the birds exchanged a blue bottle cap for a treat. As Yong writes, "the cap had no intrinsic value and the birds" and they had no idea if the same researcher would return with food. But as with the case of the stone, in majority of the cases, the birds chose the tool that had a possibility of obtaining food in the future. They published their results in the journal Science.