The
common raven (
Corvus corax), also known as the
northern raven, is a large all-black
passerine bird. Found across the Northern Hemisphere, it is the most widely distributed of all
corvids. There are at least eight
subspecies with little variation in appearance, although recent research has demonstrated significant genetic differences among populations from various regions. It is one of the two largest corvids, alongside the
thick-billed raven, and is possibly the heaviest passerine bird; at maturity, the common raven averages in length and in mass. Common ravens can live up to 21 years in the wild, a lifespan exceeded among passerines by only a few
Australasian species such as the
satin bowerbird and probably the
lyrebirds. Young birds may travel in flocks but later
mate for life, with each
mated pair defending a
territory.