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 greyish ventral fur.