Ravens found to use "hand" gestures to communicate

Ravens use their beaks and wings much like humans rely on our hands to make gestures, such as for pointing to an object, scientists now find.

This is the first time researchers have seen gestures used in this way in the wild by animals other than primates.

From the age of 9 to 12 months, human infants often use gestures to direct the attention of adults to objects, or to hold up items so that others can take them. These gestures, produced before children speak their first words, are seen as milestones in the development of human speech.

Dogs and other animals are known to point out items using gestures, but humans trained these animals, and scientists had suggested the natural development of these gestures was normally confined only to primates, said researcher Simone Pika, a biologist at the Max Planck Institute for Ornithology in Seewiesen, Germany. Even then, comparable gestures are rarely seen in the wild in our closest living relatives, the great apes — for instance, chimpanzees in the Kibale National Park in Uganda employ so-called directed scratches to indicate distinct spots on their bodies they want groomed.

Still, ravens and their relatives such as crows and magpies have been found to be remarkably intelligent over the years, surpassing most other birds in terms of smarts and even rivaling great apes on some tests.

"[What] I noticed when I encountered ravens for the first time is that they are, contrary to my main focus of research, chimpanzees, a very object-oriented species," Pika said. "It reminded me of my childhood, when my twin brother and I were still little and one of us suddenly regained a favorite toy, which existence both of us had forgotten for a little while. This toy suddenly became the center of interest, fun and competition. Similar things happen, when ravens play with each other and regain objects."