In the winter, water again permeated the ground that summer had dried out, and the botulism toxins that had accumulated in the rotted fish were ingested by water-borne invertebrates or sank to the bottom. The toxins were then ingested by the black-faced spoonbills, causing a mass die-off.
乾涸的陸地在冬季時，再為水浸泡，腐敗魚體中的毒素經水中無脊椎動物取食，或沈澱水底，被冬季來台的候鳥攝食，終於導致黑面琵鷺集體暴斃。