The Lower Keys Rabbit (Sylvilagus palustris hefneri) is a subspecies of the marsh rabbit (S. palustris), a species widespread in the southeastern United States. The Lower Keys rabbit is distinguished from the adjacent subspecies, S.p. paludicola, in skull proportions and sculpturing and in its darker coloration (Lazell 1984). The Lower Keys rabbit is about 16 inches in length, with brownish dorsal and grayish ventral fur.
The Lower Keys marsh rabbit is habitat specific, depending upon a transition zone of grasses and sedges for feeding, shelter, and nesting. This
species primarily occurs in the grassy marshes and prairies of the Lower Keys; which are transitional areas similar in form and species composition to communities interspersed throughout mangrove forests of mainland Florida (Forys and Humphrey 1994).
These wetland communities lie in the middle of the salinity gradient in the Lower Keys. Major vegetative species include grasses (Monanthochloe littoralis, Fimbristylis castaneasea); succulent herbs (Borrichia frutescens, Batis maritima, Salicornia virginica); sedges (Cyperus spp.); and sparse tree cover (Conocarpus erectus and Pithecellobium guadalupense).
Lower Keys marsh rabbits also use marshes at the fresh water end of this salinity gradient. Fresh water marsh areas are dominated by sedges like
sawgrass (Cladium jamiacense), with succulent herbs like seashore dropseed (Sporobolus virginicus) and grasses like cordgrass (Spartina spp.). Freshwater marshes are found in depressions in the interior of only a few islands, primarily in the Lower Keys. During the wet season, these areas can accumulate standing