Edgar Allan Poe knew a good Gothic trope when he saw it, and though regard for him waxes and wanes (he is now seemingly out of favor, another nineteenth-century victim of the twenty-first’s ideas of propriety), his technical skills cannot be denied. Quoth curlew or grackle or toucan: Such things are possible, but from both the semantic and the metrical standpoint, nothing works in the line so well as “raven,” yielding a nice bit of trochaic trimeter with an extra stressed end syllable.
Change that two-syllable “raven” to the one-syllable “crow,” and, curiously, the line becomes cretic dimeter (two metric feet of three syllables each: long, short, long). Formal metrics aside, “crow” just doesn’t sound right in the line—not as right as “raven.” And the raven had all the cultural credentials needed to answer the protagonist’s pressing questions: Will I ever see my departed love again? Do the good enjoy rest in heaven? Will you please stop sitting on my soul?
Poe worked from a long line of ravens in verse, and it’s entirely possible that he knew the grimmest ancestor in the grimoire, the Scottish ballad “The Twa Corbies,” in which two ravens, weak and weary, ponder the meal they’ll make of the corpse of a knight: “You will sit on his white neckbone, / and I’ll peck out his bonnie blue eyes.” The knight is dead, yet death is not complete until those ravens thatch their nests with his hair and his white bones lie exposed to the wind that will gnaw them into dust.
Though they are cousins in the tribe of birds called corvids, ravens and crows are substantially different, though easy enough to confuse. Ravens are larger than crows. Ravens are meat-eaters, as witness that poor knight, whereas crows favor seeds and fruit, dining more often on insects than equerries when more protein is wanted. Both crows and ravens are widely adapted to a range of habitats, but ravens tolerate extremes of heat and cold while crows prefer more temperate climes at the ecological edges where forests meet grasslands.
But perhaps the greatest difference is that ravens avoid human company, whereas crows seem to seek it out. Not for nothing were all those crows hanging out with gulls and other winged critters in Alfred Hitchcock’s The Birds: Unlike solitary ravens, they are social and gregarious, and they flock to cities and other human settlements with seeming disregard for the fact that humans, in turn, regularly persecute them. At best, we erect effigies to chase crows away; at worst, we turn shotguns to the sky in the effort to reduce their seemingly endless number.
For their part, most ravens know better than to come around us. In terms of sheer likeliness, then, the city-dwelling Poe would have answered the door not to a raven but to a crow on that bleak December evening. But art is made of things other than probabilities, and even if the devil is in the details, the distinction between crows and ravens is likely to remain blurry evermore.