turtledove, cuckoo
鳲 centers on a specific type of bird: the turtledove or cuckoo. The two meanings refer to related birds known for their distinctive calls.
鳲 combines 尸 (a shape that may represent a body or dwelling) with 鳥 (bird), likely forming a phono-semantic compound where 尸 hints at the sound and 鳥 indicates a bird. The exact historical development is uncertain.
The left side 尸 looks like a flag or a perch, and the right side 鳥 is a bird. Imagine a turtledove or cuckoo sitting on a perch, calling out.
For シ, picture a turtledove sitting quietly on the perch, making a soft 'shh' sound: shh -> シ, like a gentle bird call.
long-billed plover (Charadrius placidus)