National parks are not out of the woods when it comes to being overrun by invasive species. In fact, invasives have invaded about half of the parks that were created to protect native wildlife and America’s natural heritage. Species such as rats, quagga mussels (Dreissena bugensis), gypsy moths (Lymantria dispar dispar), feral hogs (Sus scrofa), goats (Capra hircus) and cats (Felis catus) are some of the 300 animals that managers are working to eradicate across national parks from Hawaii’s calderas and Alaska’s fjords to New Mexico’s Carlsbad Caverns and Florida’s Dry Tortugas. Islands are specifically vulnerable to alien species, because their unique wildlife and vegetation have evolved in an isolated area, often leaving native animals defenseless against invasives.
Read more in National Geographic.