cormorant
鸕 centers on the cormorant, a diving bird. The meaning is specific to this bird species.
鸕 combines 鳥 (bird) with 盧, which likely contributes the sound. The character was created to name the cormorant specifically.
The left side 盧 looks complex, but the right side 鳥 clearly signals a bird. Picture a cormorant perched beside a complicated fishing net structure.
For ロ, imagine a cormorant diving low over the water: low -> ロ, and the bird skims the surface.