I have always wondered what the criteria is, if any, in naming a specific corvid either a crow or raven. While the east coast American crow and the Common raven show differences, these differences are not consistant in corvids from other areas. For example, in viewing a documentary on wolves in Yellowstone, the ravens there sounded just like the American crow, and looked virtually the same, except for their face. In another documentary on the intelligance of crows, many of the birds simply called crows had the bluish tint attributed to the common raven. I cannot see any consistancy in the differentiation of the two, perhaps someone could help me out on this?