whooper swan
A large migratory swan species (Cygnus cygnus) found in northern Eurasia; winters in Japan. The katakana name is standard in field guides and everyday use.
In winter, whooper swans migrate to Japan.
I saw a flock of whooper swans at that lake.
Katakana spelling is standard for this bird species name; usually written in kana.
Kanji spelling exists but is rarely used; the katakana form is strongly preferred in modern Japanese.
From 大 (おお, 'large') + 白鳥 (はくちょう, 'swan'). The katakana spelling follows the convention for Japanese bird names.