See also this video about Partnering With Crows. (Thanks to Jonathan for the tip.)Crows have a highly developed language that includes 23 recognizable vocalizations and countless others. Corvids recognize faces; develop tools; follow crosswalk signals; and respond to humans who have both hurt and helped them. Like some urban humans, urban crows often fly out to rural areas for short breaks from urban life. University of Washington researchers are giving corvids a battery of intelligence tests usually reserved for primates.