The next day, without the box present, the birds were offered a choice between the stone tool and "distracter" objects - toys too light or bulky to use as tools.
It's not like you could ask a raven to arrange your wedding: Ravens showed they could plan by setting aside a tool that they suspected would get them a tasty treat later.
The researchers found the birds selected the tool or token about 73 percent of the time. One of the objects is the tool they can use to open the box, the others are just distractions that will not. 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. "Their performance parallels that seen in apes and suggests that planning evolved independently in corvids, which opens new avenues for the study of cognitive evolution".
As a result of the study it was deemed that ravens have the ability to plan ahead in life but not just when it comes to hiding and storing their food.
A new study showed that ravens may be smarter than we think birds.
"It is conservative to conclude that ravens perform similarly to great apes and young children", the researchers wrote. But some of them decide to stick around and sneak bits of food from humans. 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. Other apes also seem to be able to plan for the short-term future, at least up to one night.
"To be able to solve tasks like these, one needs a collection of cognitive abilities working in concert, such as inhibitory skills and different forms of memory", study author Mathias Osvath, associate professor in cognitive zoology at Lund University, said in a statement. Similar studies were also used in testing great apes and their planning skills. They also varied the time between the item selection and the task completion from 15 minutes to 17 hours, as they assessed up the raven's ability to exhibit foresight in obtaining the best outcome.
And an average of 11 out of 14 times - just less than 80% of the time - the ravens chose the tool rather than one of the distractions.
Among the tests conducted, in a number of them, the ravens performed even better that animals such as the chimps.
Taylor says this is the key control - divorcing the token from food association - that's missing from the study.
Osvath says the true question behind studying cognition is: how do all living creatures go from an "accumulation of matter" to a thinking being. One of these is their ability to see ahead. Previous studies have shown that, pound for pound, birds pack more neurons into their tiny brains than mammals, including primates.
For all we know, he told the site, those birds could be "the Albert Einsteins [of] the raven world". They even have a brain structure that's analogous to the mammalian neocortex - the part responsible for higher order functioning like conscious thought, sensory perception, spatial reasoning and language.