Different incubation temperatures result in differences in mass in female red-eared slider turtle hatchlings

Abstract

The Charnov–Bull model states that environmentally determined sex will prevail in patchy environments where males may fare best in one patch type, whereas females may fare well in a different patch type. To investigate whether or not potential differences manifest early in the life of a turtle with temperature-dependent sex determination, I assessed mass, carapace width and length, and plastron length of hatchlings from three different incubation temperature regimes. Differences in incubation temperature affected mass in turtles of the same sex; the difference appears to support a sex-based rationale for the phenotype. The results bear out an assumption of Charnov–Bull that neonates of the same sex from different temperatures may manifest different attributes (i.e., mass) that could affect their relative fitness.