SMITH: GOPHERUSPOLYPHEMUSON THE ORDWAY PRESERVE


covered with brown paper, sand, and litter to camouflage the opening. I checked
my traps in the morning, at mid-day, and in the early evening.
 The sex of adult tortoises was determined based on shell morphology (McRae
et al. 1981a). I measured straight-line carapace length (CL), plastron length (PL),
and maximum body width (CW) with 50 cm calipers, and wet body mass using a
spring scale. Tortoises were marked for individual recognition by filing a series of
notches on the marginal scutes (Cagle 1939). The date, time (Eastern Standard
Time), weather (cloudy, partly cloudy, mostly cloudy, clear, rain, or fog), and
location were noted for each capture. When a tortoise was caught at a burrow, the
width of the burrow was measured 50 cm inside the entrance (Martin and Layne
1987).
 From late April through early June 1990, 14 adult female tortoises were fitted
with radio transmitter packages (Table 1). Eight of the 14 females were caught in
sandhill habitat and six in old field. Refurbished T001RF transmitters (Advanced
Telemetry Systems, Inc., Isanti, MN) and batteries with a six-month life
expectancy were mounted on the anterior marginal scutes with epoxy gel. The
whip antennas were attached laterally to the marginal scutes with spots of epoxy
gel. Transmitter packages weighed from 30 to 35 g (less than 2% of the tortoise's
weight). Actual battery life ranged from 105 to 353 days. Transmitters were
replaced on seven females after the batteries failed.
 Tortoises were located using a Telonics 2 receiver and hand-held H-antenna.
Each tortoise was tracked at least three times a week. In addition, tortoises were
located three times a day (morning [0700-1000], mid-day [1130-1400], and early
evening [1600-2000]) for five days during the first week of each month. Numbered
wire flags were placed at each new location. Approximate locations were marked
on blue-line aerial photographs (scale 1" = 200'). Precise locations were plotted by
hand using a compass and meter tape.
 Time (EST), weather conditions, air temperature, location number, and the
tortoise's position, i.e. above or below ground, were noted each time a tortoise was
located. If a tortoise was above ground, its behavior was described as basking,
walking, feeding, nesting, or mating. To monitor activity between radio-locations,
small sticks were placed at the entrance of burrows occupied by radio-instrumented
tortoises (Hallinan 1923). Disturbance to the sticks was noted each time a tortoise
was located, and sticks were reset when necessary.
 To assess population structure, burrow censuses were conducted at selected
 sandhill sites on the Preserve (Fig. 1). Nine areas were surveyed over a six-year
 period either by myself or Richard Franz and students from the University of
 Florida (Table 2). Of the areas sampled, one (Wall Cemetery Sandhill) was
 surveyed three times over the six-year period. Surveys were conducted following
 prescribed burns because burrows were more easily detected after thick ground
 cover vegetation was removed. To conduct a census, the entire area was canvased
 by a group of people who formed a line and walked back and forth across the