<Tr> <Th_colspan="2"> Diversity </Th> </Tr> <Tr> <Td_colspan="2"> c. 45 species </Td> </Tr> <P> Corvus is a widely distributed genus of medium - sized to large birds in the family Corvidae . The genus includes species commonly known as crows, ravens, rooks and jackdaws; there is no consistent distinction between "crows" and "ravens", and these appellations have been assigned to different species chiefly on the basis of their size, crows generally being smaller than ravens . </P> <P> Ranging in size from the relatively small pigeon - sized jackdaws (Eurasian and Daurian) to the common raven of the Holarctic region and thick - billed raven of the highlands of Ethiopia, the 45 or so members of this genus occur on all temperate continents except South America, and several islands . The crow genus makes up a third of the species in the family Corvidae . The members appear to have evolved in Asia from the corvid stock, which had evolved in Australia . The collective name for a group of crows is a' flock' or a' murder' . The genus name is Latin for "raven". </P>

What is another name for a black crow
find me the text answering this question