Look at this: Ravens use referential gestures
Research report (imported) 2011 - Max Planck Institute for Ornithology
The Humboldt Research Group focuses on cognitive complexity underlying gestural signaling in three model groups to uncover the mystery of language evolution: different human cultures; closely related species; and species which live in comparable social systems. In a new study, they showed that ravens use their beaks similarly to hands to show and offer objects to conspecifics. These referential gestures may be used to test the interest of a potential partner or to strengthen an already existing relationship.