  the american crow (corvus brachyrhynchos) is a large passerine bird species of the family corvidae. it is a common bird found throughout much of north america. in the interior of the continent south of the arctic, it is referred to as simply the "crow". it is one of several species of corvid that are entirely black, though it can be distinguished from the other two such birds in its rangeâfrom the common raven (c. corax) by size and behavior and from the fish crow (c. ossifragus) by call (but see below). it is also distinguished from the raven by its smaller bill. american crows are common, widespread and adaptable, but they are highly susceptible to the west nile virus. they are monitored as a bioindicator. direct transmission of the virus from american crows to humans is not recorded to date, and in any case not considered likely. although the american crow and the hooded crow are very similar in size, structure and behavior, their calls are different. the american crow nevertheless occupies the same role the hooded crow does in eurasia. ==taxonomy== the american crow was described by christian ludwig brehm in 1822.corvus brachyrhynchos. wikispecies its scientific name means literally "short-billed crow", from ancient greek brachy- (Î²ÏÎ±ÏÏ-) "short-" and rhynchos (ÏÏÎ½ÏÎ¿Ï) "billed". the northwestern crow (c. caurinus) is very closely related to the american crow. its ancestors became separated by ice age glaciation west of the rocky mountains. it is endemic to pacific temperate rain forests where it all but replaces the american crow. only in the seattle region do they co-occur to any extent. in form the two species are much alike. there is a marked difference in voice. ===subspecies=== four subspecies are recognized. they differ in bill proportion and form a rough ne-sw clinal i
Animals_described_in_1822 Birds_of_North_America Corvus_(genus) Fauna_of_Delaware_and_Maryland IUCN_Red_List_least_concern_species Tool-using_tetrapods Urban_animals