Developmental plasticity in painted turtles, Chrysemys picta

1. The contents of newly constructed nests of Painted Turtles, Chrysemys pi cta, were manipulated by reciprocal transplant, so that each of several nes ts received a complement of eggs from each of several females. The eggs wer e recovered from nests after 8 weeks and allowed to complete incubation und er standard conditions in the laboratory. 2. Live mass, dry mass and water content of carcasses, and dry mass of unus ed yolk, varied significantly among hatchlings from eggs that incubated in different nests. Indeed, hatchlings from different nests sometimes differed as much in size or physiological condition as animals from different clutc hes. 3. Stepwise linear regression indicated that size of hatchlings and water c ontent of their carcasses were positively correlated with water exchanges b y eggs whereas mass of the unused yolk was negatively correlated with water exchanges. Although the statistical procedure is only correlative, the fin dings accord well with results of laboratory studies documenting a relation ship between uptake of water by eggs, metabolism and growth by embryos, and size and condition of hatchlings. 4. Developmental plasticity, coupled with variation in the physical environ ment within and among nests, probably accounts (minimally) for 19% of the v ariation in live mass of hatchlings in the field; 24% of the variation in d ry mass of carcasses; 11% of the variation in hydration of carcasses; and 2 6% of the variation in dry mass of unused yolk. Such variation may impact s urvival by neonatal animals, and needs to be addressed explicitly by models for the evolution of life history in Painted Turtles.