Snakes linked to stunning mammal decline in Florida Everglades

January 31, 2012 – FLORIDA – Non-native Burmese pythons are the likely cause of a staggering mammal decline in Florida’s Everglades. In PNAS journal, they report that observations of some mammal species have declined by more than 99%. A team studied road surveys of mammals in the Everglades National Park before and after pythons became common. Researchers found a strong link between the spread of pythons and drops in recorded sightings of raccoons, rabbits, bobcats and other species. The national park covers the southern 25% of the original Everglades – a region of subtropical wetlands that has been drained over the last century to reclaim it for human use. The origins of Burmese pythons in south Florida are unknown, but many were imported into the US through the pet trade. As the pythons have made it from captivity into the wild, the absence of natural predators has allowed populations to balloon. Intermittent sightings were recorded for 20 years before the snakes were recognized as being established across the Everglades in 2000. The pythons are now established across thousands of sq km in southern Florida. Although there are no accurate figures for how many there are, the numbers removed from the Everglades reached nearly 400 in 2009 and this has been increasing year-on-year (apart from a slight drop in 2010 due to a cold spell). “Any snake population – you are only seeing a small fraction of the numbers that are actually out there,’ said Prof Michael Dorcas, one of the study’s authors, from Davidson College in North Carolina. He told BBC News: “They are a new top predator in Everglades National Park – one that shouldn’t be there. We have documented pythons eating alligators; we have also documented alligators eating pythons. It depends on who is biggest during the encounter.” Earlier this month, US Interior Secretary Ken Salazar announced that the US was poised to approve a ban on importing Burmese pythons. But some observers remarked that the move was about 30 years too late. –BBC