A raven is a big black bird, ("Corvus corax"). It may be called the common raven or the northern raven. It is similar to a crow but bigger. It and the thick-billed raven are the two largest birds in the crow family, and perhaps the heaviest perching birds. The raven's feathers are all black, but a crow has feathers that are white at the bottom. This cannot be seen from a distance. 