water hen, gallinulle
鷭 centers on a specific water bird: the water hen or gallinule. It is a narrow zoological term rather than a broad conceptual kanji.
鷭 combines 番 (which likely contributes the sound ハン) with 鳥 (bird), forming a phono-semantic compound for a type of water bird.
The left side 番 suggests a number or turn, and the right side 鳥 is a bird. Imagine a numbered water hen taking its turn at the pond: 鷭 is that water hen.
For ハン, picture a water hen wearing a tiny hard hat: hard hat -> ハン, and the bird is ready for work.