High-elevation females lay larger eggs in the Atlas day gecko, Quedenfeldtia trachyblepharus (Boettger, 1873)

Identifying how reproductive investment varies along elevational gradients is a powerful tool for understanding life-history evolution in ectotherms. In taxa with invariant clutch size, reproductive responses to harsh environments are expected to be determined by per-offspring investment (egg provisioning), while at the same time being subject to maternal body size effects. We investigated elevational variation in reproductive traits of the Atlas Day Gecko, Quedenfeldtia trachyblepharus, a diurnal high-mountain species endemic to the High Atlas Mountains (Morocco). Maternal body size increased with elevation, indicating larger females at higher sites. Egg mass and egg volume increased with maternal body size, whereas relative clutch mass (RCM) declined with female size. Importantly, high-elevation females produced larger eggs than expected for their body size. Hatchling size and body condition were positively associated with egg traits, but elevation did not explain additional variation in hatchling traits once egg traits were considered. Overall, the differences observed in offspring traits appear to be mediated by maternal egg provisioning, consistent with increased per-offspring investment that may enhance offspring survival in high-elevation environments.