SMITH: GOPHERUSPOLYPHEMUSON THE ORDWAY PRESERVE


protection against predators and temperature extremes. The foraging range of
gopher tortoises probably varies depending upon resource availability. In the Texas
tortoise (G. berlandieri) daily movements were greatest in populations where food
plants were scarce or scattered (Auffenberg and Weaver 1969).
 Inter-burrow movements of telemetered females averaged 63.2 m (n = 51,
range = 10.2-375.0, SD = 63.4). The longest recorded movement between burrows
occurred in June when one female moved 375 m in an afternoon. In late May and
June, long distance movements associated with nesting were observed. Mean
length of nesting forays was 77.4 m (n = 5, range = 11.0-141.90, SD = 48.86).
 Home range size of the 14 radio-instrumented females ranged between 0.002
and 1.435 ha (Table 1). Mean home range size of females, after adjusting for
carapace length and length of time followed, were 0.482 ha (S.D. = 0.413) in
sandhills and 0.105 ha (S.D. = 0.169) in old fields. The difference between mean
home range size in the two habitats was not significant (F = 3.88, df = 13, p =
0.0771). Tortoise size and duration of observation did not explain the variation in
home range size between habitats. However, a contributing factor may be that
grasses and forbs, which constitute a major portion of the gopher tortoise's diet
(Garner and Landers 1981; Macdonald 1986; Macdonald and Mushinsky 1988),
are more abundant and evenly distributed in old fields than in sandhills
(Auffenberg and Franz 1982). Auffenberg and Iverson (1979) found that gopher
tortoise home range size was inversely related to the density of herbaceous ground
cover.
 Literature records of mean home range size of female tortoises range between
0.08 and 0.70 ha (McRae et al. 1981b; Wright 1982; Doonan 1986; Diemer
1992b). The variation may be related to differences in habitat type, geographic
location, and length of study. McRae et al. (1981b) and Diemer (1992b) also found
considerable individual variation in home range size.

 Population structure and tortoise densities.-- At seven of the nine post-burn
surveys, more than 50% of all burrows were in the adult size class (Fig. 7). These
results may be biased because subadult and adult tortoises often use more than one
burrow in a season (McRae et al. 1981b; Auffenberg and Franz 1982) and the
actual tortoise-to-burrow ratio is certainly less than 1:1. Alford (1980) suggested
that a lack of small burrows was indicative of high mortality of eggs and young.
Although small burrows are difficult to detect, I conducted my surveys following
prescribed burns to try to maximize the chance of locating small burrows.
Therefore, the truncated size class distributions probably indicate a low recruitment
rate and could reflect either a stable or declining population.
 Smith Lake and Wall Cemetery sandhills differed from the other areas in that
small size classes were well-represented (Figs. 7, 8). In the 1985 census, most
burrows at Smith Lake were in the subadult size class (140-230 mm). I surveyed a
site adjacent to Smith Lake, using transects, in 1990 and found only subadult and