1·Find out which of these are native plants and which are exotic (or nonnative).
找出其中哪些是原生植物，哪些是外来(或非本地的)。
2·Nonnative species such as feral pigs, dogs, cats, rats, goats, and cattle are a continuing threat to their food supply and eggs.
非本地物种如野猪、狗、猫、老鼠、山羊和牛继续威胁它们的食物供应和蛋。