ABSTRACT

Nonnative species mitigation is important to conserve Florida's native wildlife, especially with nonnative reptiles such as Nile Monitors (Varanus niloticus). Nile Monitors are habitat and dietary generalists in their native (Africa) and nonnative (Florida) ranges and were introduced to Florida in the early 1990s through the pet trade. Nile Monitors have since become established in three coastal counties in southern Florida. Confirmed sightings extend beyond established Nile Monitor populations into parts of central and northern Florida, but it is unclear whether spread is likely to these areas or even into surrounding states. Mitigation strategies to locate, remove, and proactively prevent introduction and spread of nonnative species include species distribution models (SDMs). Two Nile Monitor SDMs currently exist but are not at an appropriate scale to inform regional management practices and include various methods that do not meet current model quality standards. Nile Monitor SDMs here represent high-quality, region-scale predictions at a 1 km² resolution fitted with ensembles of algorithms, 14 predictors (including environmental and anthropogenic variables), and occurrence data from both the native and nonnative ranges. Final SDM predictions indicate little habitat suitability and low probability of spread beyond the central region of Florida, contradictory to existing Nile Monitor SDMs. Pathways of suitable habitat exist from established populations into other central and southern parts of Florida along coastlines and suggest possible anthropophilic habitat preferences that will require further telemetric behavioral studies to validate.