Updated

"Bird brain" may take on a new meaning, following the discovery that crafty crows can use tools to solve even complex, multi-stage tasks.

Researchers from the University of Auckland in New Zealand found that crows, already known to be clever birds, were able to solve a complex, three-stage task by applying tools to the task at hand -- or should we say beak?

The researchers captured several wild Caledonian crows and placed them in an aviary where food was just out of reach. To get it, the crows had to solve a complex problem: First pull a string to retrieve a short stick, then use the short stick to pull out a long stick, and then use the long stick to draw out a piece of meat.

The scientists split the birds into two groups with slightly different challenges, but both succeeded in reaching the food in the multi-stage task, although two of them took three or four attempts before they succeeded.

One of the birds (nicknamed Sam) spent the first 110 seconds simply inspecting the parts of the task, and then completed it the first time without error, explained Physorg.com. Another (Casper) found the string puzzling, but also completed the task on the first attempt.

Lead author Alex Taylor said finding birds that could solve a problem requiring new behaviors was "incredibly surprising," even though crows and related birds have been studied for decades because of their intelligence.

He told the Australian Broadcasting Corporation that group two faced a tougher task. "These crows had never pulled up a tool on a string before and they had never used one tool to get another tool," he says. Instead, he says, they used their previous experiences of pulling up a string and using a long tool to get food to innovate a new behavior.

The experiments showed the performance of the birds in solving the problem was consistent with a thought process -- tools can be used to retrieve unreachable objects -- rather than a process of trial and error and learning from mistakes.