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Discussion Our study demonstrated that the low (24 °C) and high (32 °C) incubation temperatures yielded significantly female-biased hatchlings, while the medium temperatures (around 28 °C) produced male-biased hatchlings or an even sex ratio of hatchlings in I G. japonicus i . Keywords: geographic variation; reptile; sex determination; sex ratio; thermal environment EN geographic variation reptile sex determination sex ratio thermal environment N.PAG N.PAG 10 04/26/22 20220415 NES 220415 1. The dataset provided daily mean air temperatures, daily maximum air temperatures, and daily minimum air temperatures of 30-year means: (a) mean air temperature; (b) maximum air temperature; (c) minimum air temperature. In our species, maternally derived yolk steroid hormones interact with incubation temperatures to affect offspring sex ratio, with substantial effects of yolk hormones on offspring sex ratio at the medium temperature of 28 °C [[14]]. [Extracted from the article]

Despite the importance of maternally selected nests in shaping offspring phenotypes, our understanding of how the nest environment affects embryonic development and offspring traits of most non‐avian reptiles is rather limited largely due to the logistical difficulty in locating their nests. To identify the relative contributions of environmental (temporal [seasonal] and spatial [nest‐site]) and intrinsic (clutch) factors on embryonic development and offspring traits, we conducted a cross‐fostering experiment by swapping eggs between maternally‐selected nests of the toad‐headed agama (Phrynocephalus przewalskii) in the field. We found that nest environment explained a large proportion of variation in incubation duration, hatching success, and offspring size and growth. In contrast, clutch only explained a small proportion of variation in these embryonic and offspring traits. More significantly, compared with spatial effects, seasonal effects explained more phenotypic variation in both embryonic development and offspring traits. Eggs laid early in the nesting season had longer incubation durations and produced smaller hatchlings with higher post‐hatching growth rates than did later‐laid eggs. Consequently, hatchlings from early‐laid eggs reached larger body sizes prior to winter. In addition, we found that female toad‐headed agama did not select nests specific to reaction norms of their own offspring because hatchlings from original or translocated nests had similar phenotypic traits. Overall, our study demonstrates the importance of seasonal variation in nest environments in determining embryonic development and offspring phenotypes, which has not been widely appreciated at least in non‐avian reptiles. [ABSTRACT FROM AUTHOR]