 A common question that I get is, how do you tell an American crow from a common raven? They can be challenging to tell apart. The first one, if you get a relatively good look at that at them, is by the pattern of the tail. Second is the size of the two species. So, American crow is about a third smaller than the common raven. Common ravens much larger and they've got a much thicker bill than the American crow. Finally, and perhaps most easily, is their vocalizations. So, the American crow kind of gives the standard... The common raven, though, makes a lot of really odd calls. You know, croaks and screams, just a lot of different vocalizations. Things like... So, that's really the easiest way to tell these two species apart.