crow, raven
鴉 centers on the crow or raven, the large black bird. The two meanings are essentially the same animal, with no distinct conceptual split.
鴉 combines 牙 (which likely contributes the sound) with 鳥 (bird), forming a phono-semantic character for the crow or raven.
A bird (鳥) with a tusk-like beak (牙) that caws loudly: that's a crow or raven.
For ア, imagine a crow opening its beak wide and letting out a loud 'Ah!' sound: 'Ah!' -> ア, the crow's cry.
common raven (Corvus corax)
jungle crow (Corvus macrorhynchos)
carrion crow (Corvus corone)
The Raven (narrative poem by Edgar Allan Poe)
winter crow
crow cawing in the morning; crows crying in the morning
blacker than black
glossy black (hair); color of a crow with wet feathers
jet-black hair
Australian magpie (Gymnorhina tibicen)