moorhen; waterhen; gallinule
Refers to the common moorhen (Gallinula chloropus), a waterbird found in wetlands. Usually written in katakana as バン.
I saw a moorhen swimming in the pond.
Hiragana spelling is also used, but katakana is more common for animal names.
Kanji form is very rare and may not be recognized by many readers.
The Japanese name バン is likely derived from the bird's call or an onomatopoeic representation. The kanji 鷭 is a kokuji (Japanese-created character) combining 鳥 (bird) and 番 (watch/guard), but the exact origin is uncertain.