Responding to questions about how the spoonbills had contracted botulism, the COA offered this possible scenario: A recent cold front had killed fish being raised in fish ponds near the spoonbills 'nesting site, and rotting fish can contain the type C1 botulism bacterium. Spoonbills usually eat only fresh fish, but this year more spoonbills than usual are wintering in Taiwan, increasing the competition for food.
農委會猜測，日前寒流來襲，導致黑面琵鷺棲地附近魚塭的養殖魚類死亡，由於腐魚體內含有「Ｃ１型肉毒梭狀桿菌毒素」，而今年飛抵台灣渡冬的黑面琵鷺又較往年多，原本只愛新鮮魚類的黑面琵鷺，因為食物需求量增加，在歷經長途跋涉後，可能為求裹腹，只得吞下腐敗魚肉。