Non-native Burmese pythons are believed to be the cause of severe mammal declines in the Florida Everglades, according to new research. Also known as the Asiatic rock python, the Burmese python (Python molurus bivittatus) is a large constricting snake native to Asia. The exact origins of the pythons in the Everglades are unknown, but many have been imported into the United States through the pet trade, and some are likely to have escaped or been released into the wild. In the absence of natural predators, the Burmese python population has exploded. Since 2000 the species has been recognised as being established across large parts of southern Florida, where it is known to eat a wide variety of mammals and birds. In new research published in the journal PNAS, a team of scientists studied the number of live and dead mammals spotted along roads in the Everglades National Park. The team compared mammal surveys performed before and after the pythons became common, and found a strong link between the spread of the snakes and a decrease in many mammal species. In particular, observations of racoons and opossums dropped by about 99%, while white-tailed deer fell by 94% and bobcats by 87.5%. No rabbits or foxes were seen during more recent surveys, despite rabbits being one of the most common mammals in earlier studies.