To maximize potential fitness, reproductive females should invest available resources in either larger propagules (egg and/or hatchling size) or more propagules (clutch size). Females may also enhance offspring performance by selecting nest sites with optimal conditions for the developing eggs. This study examined maternal investment in a population of spotted turtles (Clemmys guttata) in Ontario, Canada over 2 y using radio telemetry, x-ray photography, and indirect assessments of hatchling fitness. Analyses were conducted at 2 scales (clutch and female), utilizing 2 measures of available resources (body size and body condition). Larger females produced wider eggs, and similarity in the slopes of egg width and maternal pelvic aperture on body size may indicate a physical constraint on egg size. However, body size did not explain variation in egg morphometrics (length, width, or mass) when considering the reproductive output of each female over the entire study. Instead, females in better body condition produced more eggs. With respect to nest site selection, no selection for thermal properties was observed, and females exhibited stronger fidelity to nest substrates than to nest locations. Hatchling righting response was not related to hatchling body size or condition, but hatchlings from a clutch performed similarly, indicating maternal genetic effects or an effect of nest conditions. Thus, females in good condition maximize the number of eggs produced over multiple years, and hatchling morphometrics may not directly influence hatchling success.

Nomenclature: Ernst & Lovich, 2009.