Chelydra serpentina

Smith, Geoffrey R., Iverson, John B. & Rettig, Jessica E., 2022, Do observed sex ratios in a turtle community in northern Indiana vary over 35 years (1979 - 2014)?, Amphibian & Reptile Conservation (e 309) 16 (1), pp. 193-202 : 195

• C. serpentina , 11.2 ± 1.5 (n = 18 years; range: 1–23); • C. picta , 93.5 ± 11.4 (n = 30 years; range: 13–259); • G. geographica , 12.5 ± 1.7 (n = 28 years; range: 1–42); • S. odoratus , 79.0 ± 9.2 (n = 30 years; range: 4–189);

• T. s. elegans, 9.9 ± 1.3 (n = 22 years; range: 1–18).

Chelydra serpentina . The overall mean proportion of males by year was 0.66 ± 0.04 (n = 18), which is significantly different from 0.5 (t 17 = 3.56, p = 0.0024). Using only years with> 10 individuals, the mean proportion of males was 0.69 ± 0.03 (n = 10), which is also significantly different from 0.5 (t 9 = 5.86, p = 0.0002). The proportion of males was not affected by year, trap type, or the total number of individuals ( Table 1).

Chrysemys picta . The overall mean proportion of males by year was 0.47 ± 0.02 (n = 30), which is not different from 0.5 (t 29 = -1.52, p = 0.14). Year, trap type, and the total number of individuals had no effect on the proportion of males found in a given year ( Table 1).

Graptemys geographica . The overall mean proportion of males by year was 0.53 ± 0.04 (n = 28), which is not significantly different from 0.5 (t 27 = 0.69, p = 0.50). The mean proportion of males in years with> 10 individuals was 0.46 ± 0.04 (n = 14), which is also not significantly different from 0.5 (t 13 = -0.94, p = 0.36). The proportion of males in a year was not affected by year, trap type, or the total number of individuals ( Table 1).