The native mammals of the Florida Everglades have been all but wiped out by huge numbers of pythons and anacondas descended from released pets, a new study finds. After nearly a decade of night-time road surveys in the 1.5 million-acre national park, researchers found that raccoon and opossum sightings were down 99% from the '90s, the Washington Post reports. Bobcat sightings were down 88%, and not a single rabbit or fox was seen, dead or alive.
The researchers blame the dramatic decline on the snakes, which can grow to be more than 20 feet long and are fighting—often literally—with alligators to be top of the food chain. "There aren’t many native mammals that pythons can’t choke down," one of the study's authors says. Florida wildlife officials have hired python hunters, but experts say it may be impossible to eradicate the snakes from the Everglades and advise that more research be done on how to stop them from spreading to other areas of Florida and even other states.