<Tr> <Td_colspan="2"> Roughly 100 families, around 5,400 species </Td> </Tr> <P> A passerine is any bird of the order Passeriformes, which includes more than half of all bird species . Passerines are distinguished from other orders of Aves by the arrangement of their toes, three pointing forward and one back, which facilitates perching . </P> <P> Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders, with over 5,000 identified species . It has roughly twice as many species as the largest of the mammal orders, the Rodentia . It contains more than 110 families, the second-most of any order of tetrapods (after Squamata, the scaled reptiles). The passerines contain several groups of brood parasites such as the viduas, cuckoo - finches, and the cowbirds . Most passerines are omnivorous, while the shrikes are carnivorous . </P> <P> The names "passerine" and "Passeriformes" are derived from Passer domesticus, the scientific name of the eponymous species (the house sparrow) and ultimately from the Latin term passer for Passer sparrows and similar small birds . </P>

What is the difference between psittacines and passerines