The raven at 24 inches long, is half again as big as the crow at 17 inches. Unfortunately they will rarely give you such an easy side by side comparison. More commonly you see them at some distance ...

AUBURN, N.Y. — Despite the crow’s reputation as a destructive pest, villain and harbinger of trouble, a hunting contest to thin the swarms of crows that winter in Auburn gives the city a black ...

And since the large and noticeable, black raven primarily survives by feasting on carrion, the bird came to represent darkness and death, sin and sinning to many ancient and medieval civilizations.