Because of limitations in terms of time and space and questions concerning the sufficiency of research information, the film only documents five varieties of the bird--the roseate tern, the little tern, the black-naped tern, the brown noddy, and the bridled tern.
由於限於時空的條件及研究資料的足夠與否，片中只記錄了紅燕鷗、蒼燕鷗、玄燕燕鷗等五種。