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A large, all-black passerine bird.
Scientifically, crows are one species of bird in the broader Corvidae family, which includes crows, ravens, rooks, jackdaws, jays, magpies, treepies, choughs, and nutcrackers. On Danbooru, "crow" includes all visually-similar birds in the Corvidae family.
Birds in the Corvidae family range in size from the relatively small pigeon-size jackdaws (Eurasian and Daurian) to the Common Raven of the Holarctic region and Thick-billed Raven of the highlands of Ethiopia. The 40 or so members of Corvus genus occur on all temperate continents (except South America) and several offshore and oceanic islands.
Crow species found in Japan, aside from magpies, jays and nutcrackers, include the rook, carrion crow, Eurasian & Daurian jackdaws, the large-billed crow, and the common raven.
Touhou characters Shameimaru Aya and Himekaidou Hatate are crow tengu, while Reiuji Utsuho is a hell raven youkai.