Meeting Abstract
P3.148 Tuesday, Jan. 6 Nest temperatures and offspring phenotype in the painted turtle: Does the magnitude of temperature fluctuations matter? CLAIRARDIN, S.G. *; GRIFFIN, A.M.; HOLGERSSON, M.C.N. ; PAITZ, R.T. ; BOWDEN, R.M. ; Illinois St. Univ.; Illinois St. Univ.; Illinois St. Univ.; Illinois St. Univ.; Illinois St. Univ. sgclair@ilstu.edu
Maternal effects have been shown to impact offspring development. In oviparous reptiles, studies utilizing constant laboratory incubations have demonstrated that incubation temperatures can influence a suite of phenotypic traits, including sex. Recent work has investigated how more natural fluctuating temperatures influence offspring phenotype and shown that temperature fluctuations can produce effects that differ from what would be predicted under constant incubation conditions. This study aims to investigate the potential for female painted turtles (Chrysemys picta) to use vegetation cover as a predictor of temperature fluctuations within the nest. This relationship was characterized for 16 natural nest sites using temperature loggers to record nest temperatures and digital imagery to quantify vegetation cover. To study phenotypic outcomes of temperature fluctuations, eggs from eleven clutches were allocated to one of three incubation regimes: constant temperature (27°C), four degree fluctuation (27+/-4°C), and eight degree fluctuation (27+/-8°C). Data from natural nests indicate that daily maximum temperature, daily mean temperature, and daily temperature range, but not daily minimum temperature, were related to overstory cover. In the lab, temperature fluctuations had a significant effect on incubation duration, but not hatchling length, mass or plastron coloration. Additional parameters of offspring phenotype will be measured including righting time, immunocompetence (both cell-mediated and humoral), and sex. The findings from this study indicate that overstory cover can affect nest temperature fluctuations, which can ultimately influence offspring phenotype.
