A short, rounded occipital crest sat at the back of the head; its syringeal bulla was flattened, rather than rounded as in other pochards.    From Wordnik.com.  [The Madagascar pochard returns] Reference

Features of its syringeal bulla are unique, it has that rounded, bushy head crest, and various details of the plumage on its flanks, wings and neck are unique.    From Wordnik.com.  [The Madagascar pochard returns] Reference

Mimics and others that produce a wide variety of bird song sounds, like the crow, mockingbird, and starling have a greater number of syringeal muscles.    From Wordnik.com.  [Clipmarks | Live Clips] Reference

Vincennes, "and something just as creditable to his talent, too -- dissected many birds with special reference to this subject, and gave close attention to birds in the act of singing, both out of doors and in captivity, and I am convinced that he proved the theory of the syringeal origin of bird song to be an erroneous one.    From Wordnik.com.  [Our Bird Comrades] Reference