The earliest count of the kite population in Taiwan was made only in the early 1980s. Yen Chung-wei, an assistant researcher at the National Museum of Natural Science in Taichung, drove around the island to do a survey. He stated that there were at that time probably between 150 and 200 black kites in Taiwan.
目前國內有關鳶口的數量記錄，最早只能追溯到一九八○年代初期，台中自然科學博物館副研究員顏重威開車做環島調查後，曾提及台灣老鷹大約有一百五十到兩百隻。