Common Raven (Corvus corax)
The true crows are large passerine birds that form the
genus Corvus in the family Corvidae. Ranging in size
from the relatively
(Eurasian and Daurian) to the Common Raven of the
Holarctic region and Thick-billed Raven of the highlands
of Ethiopia, the 40 or so members of this genus occur on
all temperate continents (except South America) and
several offshore and oceanic islands (including Hawaii).
In the United States, the word "crow" is used to refer to
the American Crow. The crow genus makes up a third of
the species in the Corvidae family. Other corvids include
rooks and jays. Crows appear to have evolved in Asia
from the corvid stock, which had evolved in Australasia.
A group of crows is called a "murder," though this term
usually appears in poetry rather than scientific contexts.
The genus was originally described by Linnaeus in his
18th century work Systema Naturae. The name is de-
rived from the Latin corvus meaning "raven". The type
species is the Common Raven (Corvus corax); others
named in the same work include the Carrion Crow (C.
corone), the Hooded Crow (C. cornix), the Rook (C. fru-
gilegus), and the Jackdaw (C. monedula).
There is no good systematic approach to the genus at
present. Generally, it is assumed that the species from a
geographical area are more closely related to each other
than to other lineages, but this is not necessarily correct.
For example, while the Carrion/Collared/House Crow
complex is certainly closely related to each other, the
situation is not at all clear regarding the Australian/
Melanesian species. Furthermore, as many species are
similar in appearance, determining actual range and
characteristics can be very difficult, such as in Australia
where the five (possibly six) species are almost identical
The fossil record of