Wu Jen-pang says that previously Kuantien water caltrop farmers sprayed their crop with pesticides to kill off the moorhens and jacanas that fed on the caltrops, and the jacanas as well as other birds were affected.
吳仁邦表示，以前官田菱農因為紅冠水雞會啄食菱角，因而噴灑農藥置鳥兒於死地，常禍連水雉和其他鳥兒。