The birds of the family corvidae appear to be a clever bunch - The New Caledonian crow, for example, can fashion very primitive tools and to use them to extract grubs from crevices in trees. So perhaps it is no surprise that Scientists have revealed that the Raven is a bird of surprising intelligence (okay so no Raven is going to be designing a nuclear reactor anytime soon but even so...)
Writing in the Scientific American Bernd Heinrich and Thomas Bugnyar describe a series of experiments that demonstrate the bird’s intelligence. In one experiment ravens were allowed to sit on perches from which pieces of meat dangled from string. But to get the treat, the raven had to perform a complex series of actions: pull up some of the string, place a loop on the perch and hold it with a claw, then pull up another section of string and hold that loop on the perch. By repeating this process half a dozen times, a raven could reach the end of the string and get the meat.
'Some animals can be taught how to get food this way,' Heinrich said. 'However, I found ravens could perform this complex sequence of actions straight away. These birds have never seen string before or encountered meat hanging this way, yet they worked out exactly what they needed to do to get a treat.'
Many animals, birds and insects are capable of carrying out complex actions: nest-building, for example. However, such creatures are programmed genetically to undertake the different steps involved in such behaviour. Little intelligence is involved. By contrast, ravens have demonstrated that they can work out complex sets of actions, involving no tests or trial and error. This implies that they use logic. 'The birds acted as if they knew what they were doing,' the two researchers say in Scientific American. 'Ravens have the ability to test actions in their minds. That capacity is probably lacking, or present only to a limited extent, in most animals.'
Other experiments show that Ravens will let other animals do work for them. In the wild, they have been known to make calls that bring wolves and foxes to dead animals so that these large carnivores can break the carcass apart, making meat accessible to the birds. Scientists believe that ravens evolved their intelligence because of their complex social lives and scavenging lifestyles.