The Distribution and Population Dynamics of the Golden Mouse (\u3cem\u3eOchrotomys nuttalli\u3c/em\u3e) at Its Southern Range Periphery

This research assesses the status of the golden mouse (Ochrotomys nuttalli) in Florida by taking a multi-pronged approach. Geographic Information Systems (GIS) was used to understand the distribution of habitats and occurrence records for this species within the state. Presence-absence trapping occurred at 13 study sites to determine if historic southern periphery populations were still occupied, gauge if more central populations were being maintained, and document golden mice in previously unrecorded areas. In addition, surveys for O. nuttalli took place at regular intervals at the USF Ecological Research Area to understand how populations of this species fluctuate over time and ensure that individuals could be caught during the months when statewide trapping was occurring. Trapping data from all 14 sites were combined to determine a level of confidence for absences at each site which did not yield a golden mouse capture. Finally, I determined the relative abundance of golden mice relative to other small mammal species caught. Locality records for this species align closely with the distribution of hardwood-containing habitats in Florida. The distribution of O. nuttalli is not continuous across Florida and becomes increasingly patchy near the southern range periphery of this species. In south-central Florida, populations are restricted to regions where hardwoods extend south along one of three upland ridges. Golden mice were determined to be present in the vicinity of the southernmost historic sites on each of these ridges. Ochrotomys nuttalli were captured at six of the 13 sites surveyed. At the USF Ecological Research Area, O. nuttalli were captured in all months surveyed although abundances remained relatively low from October through January and then increased from February through May. At study sites which did not catch a golden mouse, 78.6 to 100% of the trapping periods which successfully caught a golden mouse had done so by the effort levels invested at these absent sites. Ochrotomys nuttalli was the fourth most abundant of 12 species captured, but several of the species caught less frequently than golden mice are non-native or too large to have their true abundance reflected by these trapping methods