BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL. 38 PT. 1(4)


Table 8. Hatchling gopher tortoise measurements for the Ordway Preserve, Putnam County, Florida.
Measurements are in mm.

 Carapace Length' Wet Body Massb

 Year N Mean Range SD N Mean Range SD

 1990 36 48.0 41.0-51.8 2.56 36 30.0 18.2-38.8 3.94
 1991 74 42.3 32.0-47.0 2.73 73 33.3 27.0-43.0 4.65

SMean caapace length in 1990 was significantly different from 1991 (= 10.30, d. = 108,P< 0.001).
b Mean wet body mass in 1990 was significantly different from 1991 (r = -3.88, d. = 80,P<0.001).



movements must be provided to ensure recruitment of new individuals into the
population.
 Differences in home range size related to habitat also must be considered in
determining the optimum size of preserves. Minimum area requirements of
tortoises in sandhills, where food plants are scattered, probably are greater than in
ruderal sites, where herbaceous cover tends to be thick.
 Under favorable conditions, minimum viable population size for the gopher
tortoise has been estimated to be 40 to 50 individuals (assuming a 1:1 adult sex
ratio) (Cox et al. 1987). Based on home range estimates from this study, 20 female
tortoises in sandhills would require 10 to 30 ha of habitat and those in old fields
2 to 10 ha. Home ranges probably overlap, and males and juveniles tend to use a
larger area than females (McRae et al. 1981b; Diemer 1992b). Estimates of area
requirements may be useful in determining size of recipient sites for tortoise
relocation and reintroduction projects. Research is needed to fully evaluate the
carrying capacity of different habitats.
 Burrow densities and tortoise population structure on the Ordway Preserve
varied by location, reflecting the effects of past harvest. Effects of harvest prior to
1979 still were evident in 1990 at a site near the center of the Preserve. Tortoise
populations are slow to recover from the impacts of harvest as a result of low
reproductive potential and high egg and hatchling mortality. These life history
constraints limit the ability of tortoise populations to recover from other human
impacts such as habitat alteration.
 Clutch size, nesting dates, and incubation period on the Ordway Preserve
were comparable to previous studies conducted in north-central Florida. However,
in contrast to reports in the literature, it appears that many female tortoises on the
Ordway Preserve deposit their eggs away from burrow entrances and that nests at
burrow aprons are not necessarily those of resident females. Studies are needed to