SMITH: GOPHERS POLYPHEMUS ON THE ORDWAY PRESERVE


 350


 300 -



 S200 -
 I- I
 S250 -
 -J







 100
 80 120 160 200 240 280 320
 BURROW WIDTH (mm)

Figure 9. The relationship between burrow width and carapace length for gopher tortoises on the Katharine
Ordway Preserve, Putnam Co., Florida. The regression equation is: Carapace length = 62.049 + 0.71
(Burrow width).



small adult-size burrows. Prior to 1979, tortoises in the area had been hunted (T.
Perry and R. Franz pers. comm.). Assuming that large tortoises were removed from
this population as recently as 1979, hatchling and small juvenile individuals from
that period would be expected to be subadults or small adults in 1990. It appears
that adult tortoises have not immigrated into this area.
 Surveys at three-year intervals at Wall Cemetery (WC) revealed a shift from
primarily juveniles in 1985 to adults in 1991 (Fig. 8). This population also was
harvested prior to 1979. The observed changes in population structure may reflect
growth of individuals from the 1985 population and immigration from surrounding
areas.
 Estimated carapace length was calculated using the regression line generated
from 64 pairs of carapace length and burrow width measurements. Burrow width
was a good indicator of tortoise size (Fig. 9); the fit to the data was significant (t =
18.35. df = 62, p < 0.0001. r = 0.92). Mean estimated CL at core sandhill and old
field sites were significantly different (t = 2.38, df = 20, p < 0.025). The core
sandhill site, as mentioned above, was harvested prior to 1979. Burrow density at
the core sandhill site (2.42 burrows per ha) was comparatively low, reflecting the
removal of sexually mature individuals.