Low levels of mercury in the diet of male white ibises cause the birds to mate with each other rather than with females. As a result many of the females can't breed, and fewer chicks are produced.

雄白鹮因吃了含有少量汞的食物而改变性取向，不再与雌白鹮交配，导致为数不少的雌白鹮无法生育，后代数量持续下降。