Hatching success in relation to egg size in painted turtles (Chrysemys picta)

Abstract
Most hypotheses addressing the significance of intraspecific variation in size of reptilian eggs have focused on potential benefits accruing to the large hatchlings that usually emerge from large eggs. We find, however, that large eggs of painted turtles (Chrysemys picta) have a significantly higher probability of hatching than do small eggs incubated under many conditions of temperature and moisture. Surface area to volume considerations may account for differences in hatching success between large and small eggs incubated in dry conditions. Natural selection for size of reptilian eggs may therefore be more intense than has been suspected heretofore, because differential mortality related to egg size probably occurs in prenatal as well as early postnatal stages in the life cycle.