Fig. 4. Values for the limit of supercooling for individual painted turtles that hatched from eggs incubated on natural soil in the laboratory. Unacclimated animals were studied within days of the time they hatched; animals in the high acclimation group were held at 24°C for 6 weeks; turtles in the low acclimation groups were acclimated to 3°C over periods of 6 weeks and 15 weeks. The distribution of values for unacclimated animals differs from the distribution for turtles acclimated at high temperature (Wilcoxon two-sample test, z=4.87, P<0.001), and the distribution for the latter differs from that for hatchlings acclimated at low temperature for 6 weeks (Wilcoxon two-sample test, z=5.40, P<0.001). Data are from Packard and Packard (2003c).