New Guinea Flatworm Inventory (Tree Snails) at Everglades National Park and Big Cypress National Preserve 2021-2024 - Open Format Dataset

The New Guinea Flatworm (Platydemus manokwari) (NGF), is a non-native terrestrial predator of snails and other invertebrates that has been introduced into Florida. The NGF has been shown to be responsible for dramatic declines in native land snail populations in other parts of the world. The goal of this study was to survey sites in both Everglades National Park (EVER) and Big Cypress National Preserve (BICY) for native tree snails and flatworms in sites ranging from high-use areas to low use areas. Tree snails were surveyed during the day by meander surveys to determine presence/absence, followed by timed transects following meander survey success. Flatworms were surveyed at night, again by meander surveys to determine presence, followed by timed quadrat sampling. Flatworm specimens were genetically analyzed by Cytochrome Oxidase 1 (COI) barcoding to confirm species identification. A total of 5,855 observations of tree snails were recorded for three species of native tree snails, Orthalicus floridensis, Orthalicus reses, and Liguus facsiatus. Night surveys yielded 1,263 observations of flatworms representing 9 different species. Living tree snails, or evidence of their past occurrence in the form of shells, were found at most of the surveyed sites with suitable habitat. New Guinea Flatworm occurred more commonly at high-use sites than low use sites. These results suggest that the invasion of NGF into EVER and BICY appears to be less severe than in more developed/urban areas. Several recommendations to limit the further spread of NGF in these protected areas are included in this report.