Eurasian bittern
The calls of the buffy fish owl are described as a deep humming "boom-uh-boom", a "hup hup hu" and a loud "huhuhuhuhuhuhu". A trisyllabic "tu-hoo-hoo" is seemingly the territorial song emitted before breeding. Its call has been described as comparable to that of a distant Eurasian bittern ("Botaurus stellaris").