Borrowed from English emu. Borrowed via Cantonese.
鴯鶓
Orthographic borrowing from Chinese 鴯鶓/鸸鹋 (érmiáo), Cantonese 鴯鶓/鸸鹋 (ji4 miu4).
鴯鶓(エミュー) • (emyū) ←エミウ (emiu)?