WARNER, D.A.*; ANDREWS, R.M.: Maternal and Environmental Contributions to Hatchling Phenotypes and Survival of the Lizard Sceloporus undulatus

Phenotypic variation of hatchling reptiles is influenced by environmental conditions during egg incubation and by various maternal sources. We investigated the effects of incubation moisture conditions, maternal yolk investment, and clutch on various phenotypic traits and subsequent survival of hatchlings of the lizard, Sceloporus undulatus. Eggs from 28 clutches were incubated under two moisture regimes (-150 kPa and -530 kPa) to evaluate the effect of incubation moisture on hatchling phenotypes. Yolk was removed from eggs in another treatment to evaluate the effect of yolk investment on hatchling phenotypes. After hatching, snout-vent length, mass, tail length, growth rate, thermal preference, running speed, and desiccation rate were measured for each hatchling. Hatchlings were released at a field site near Blacksburg, Virginia and monitored until winter and again the following spring. Incubation moisture had a small effect on hatchling body size; hatchlings incubated under wet conditions were slightly larger than those from dry conditions. Maternal yolk investment had a similar effect on hatchling body size; eggs with yolk removed resulted in small bodied hatchlings. Neither incubation moisture nor yolk investment had an effect on performance; clutch explained most of the variation in phenotypes. Similarly, survival was not affected by treatment, but was associated with clutch. Hatchlings that survived longer than 6 weeks grew more slowly than those that did not survive to six weeks. Assuming rapid growth rate is associated with high activity, the more rapidly growing hatchlings could have been conspicuous to predators. In general, our observations demonstrate the importance of maternal (clutch) contributions to offspring fitness.