PS 20-59 - Investigating the influence of environmental covariates on marsh rabbit occupancy in southwest Florida

Tuesday, August 8, 2017
Exhibit Hall, Oregon Convention Center
Modeline Celestin1, Hanna Innocent1, Nichole Bishop2, Christina M. Romagosa3, Ray Carthy4 and Wesley W. Boone IV5, (1)Doris Duke Conservation Scholars Program, Gainesville, FL, (2)School of Natural Resources & Environment, University of Florida, Gainesville, FL, (3)Wildlife Ecology and Conservation, University of Florida, Gainesville, FL, (4)FL Coop Fish and Wildlife Unit, University of Florida, Gainesville, FL, (5)Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, FL

Our understanding of habitat associations regarding relatively common wildlife species is often superficial. However, the onset of the world’s sixth mass extinction necessitates a better comprehension of every species’ ecology. In this study we investigated how vegetative structure influenced marsh rabbit (Sylvilagus palustris) occupancy on Sanibel Island, Florida. Field work took place on eight grids randomly selected across Sanibel Island, Florida during summer 2016. On each grid, we conducted transect surveys for marsh rabbit scat. Presence and absence of marsh rabbit scat were recorded. Density of vegetation was measured along each transect using a Robel pole, and data on dominant vegetative species was collected. Dominant species recorded included buttonwood (Conocarpus erectus), sand cordgrass (Spartina bakeri), and giant leather fern (Acrostichum danaeifolium). Additionally, we collected a binary measure of water inundation at each site. We investigated the influence of vegetative structure, composition, and inundation on marsh rabbit occupancy probability using 12 a priorimodels in Program Presence. We considered variables with 95% confidence intervals not crossing zero to be statistically significant.


We found that the percentage cover of bare ground, leather fern, and cordgrass best accounted for variation in occurrence of marsh rabbits on our grids. Increases in cordgrass and leather fern coverage were correlated with increases in marsh rabbit occurrence, while increases in bare ground coverage were negatively associated with occurrence. Models inclusive of inundation did not converge. No variables were found to significantly influence detection. These findings reveal the importance of grassland vegetation species to marsh rabbits; an important observation from an increasingly shrub-encroached system.