http://phys.org/news/2012-10-clever-crow-bird-brain.html
In the chapter CLEVER CORVIDS in NAC there is a lot of information about the extraordinary cognitive abilities of new Caledonian crows - particularly with regard to their intelligence and dexterity in using tools to retrieve food. In this lovely piece of scientific work, researchers, using field of vision cameras, have determined that these crows have much better binocular vision than most birds, and indeed, than other members of the crow family and other corvids. "the binocular overlap is 61.5 degrees, which is at least 23.9 degrees greater than in non-tool-using species of crow that the researchers also examined." This allows them to judge distance much better than other animals with eyes mounted on the sides of their heads and explains why these crows are much better tool users than birds with similar powers of cognition.