54 
C. Kenneth Dodd, Jr. 
Table 1. Relationship between the dependent variables (Y) of plastron length 
(PL) and body mass (W) and the independent variables (X) of carapace 
length (CL) and plastron length for Brushy Lake Sternotherus 
odoratus. For correlations involving body mass, the data were log-log 
transformed. Units in g and mm. The statistical significance of 
correlation coefficients is indicated (**, P< 0.01). 
Sex 
Y 
X 
N 
b 
a 
r 
F 
PL 
CL 
70 
0.6186 
8.6734 
0.8839** 
J 
PL 
CL 
10 
0.7389 
-1.8576 
0.9873** 
M 
PL 
CL 
28 
0.5392 
10.1843 
0.8876** 
Total 
PL 
CL 
108 
0.6638 
3.7944 
0.9147** 
F 
W 
CL 
70 
2.7797 
-7.6707 
0.9313** 
J 
W 
CL 
10 
2.8811 
-8.0973 
0.9943** 
M 
W 
CL 
28 
2.7154 
-7.4658 
0.9616** 
F 
W 
PL 
70 
2.8170 
-6.9657 
0.9033** 
J 
W 
PL 
10 
2.6267 
-6.1680 
0.9872** 
M 
W 
PL 
28 
2.8640 
-6.9762 
0.9143** 
M+F 
W 
CL 
98 
2.7066 
-7.3767 
0.9346** 
M+F 
W 
PL 
98 
2.5299 
-5.7731 
0.8592** 
Total 
W 
CL 
108 
2.7853 
-7.7164 
0.9799** 
Total 
W 
PL 
108 
2.6152 
-6.1140 
0.9581** 
Assuming a density of 148.5 S. odoratus /ha in Brushy Creek Lake, 
there was a minimum biomass of 10.6 kg/ ha. 
Body mass may vary seasonally, especially among females (e.g., 
Branch 1984), and it may be among the most important variables in life 
history studies (see Hedges 1985 and references therein). As such, 
variation in body mass between populations of turtles may be of greater 
importance than recognized to date. As Congdon et al. (1986) suggested, 
factors such as habitat suitability, body size, and population age structure 
may be more important in determining species-specific densities than 
trophic position. 
Mortality. On 3 June, 41 of 56 S. odoratus drowned in traps, 
presumably because of high water temperature and low oxygen concen- 
tration in the unshaded study site. These included 28 females, 4 males, 
and 9 juveniles. There was no significant difference in the sex ratio of 
drowned animals and the overall sex ratio of turtles that did not drown 
(X 2 = 3.35, P - 0.067) or between the carapace lengths of drowned (x = 
75.2 mm, SD = 6.6) and non-drowned (x = 75.5 mm, SD = 5.9) adults (F 
= 0.03; P - 0.87). Also, there was no relationship between the sex of the 
turtles and their CL on their tendency to drown (F = 0.03; P = 0.85). 
Although Ultsch et al. (1984) reported that S. odoratus could 
survive submergence 5.2 days under anoxic conditions at 10° C, my 
trap results suggest that stinkpots have considerably less tolerance to 
