Thermal conditions during pregnancy affect the length of gestation and phenotype of offspring in viviparous lizards. However, past studies have typically exposed females to basking treatments throughout pregnancy, meaning that effects specific to late pregnancy (including cues for parturition) or to night temperatures are poorly understood. We examined effects of thermal treatments during late-embryonic development on Woodworthia ‘Otago/Southland’, a viviparous gecko with an unusual capacity to reproduce annually or biennially. Among females from a cool-climate, biennially reproducing population, elevated levels of basking opportunity and night temperature during late summer together increased the proportion of births occurring before winter in the laboratory. Offspring born before winter also had higher mass and body condition than those born after winter. Regardless of the season, the daytime body temperature of females declined shortly before parturition (putatively assisting survival of fully developed embryos in utero), then increased immediately after parturition to match that of neonates. Overall, the combined effects of warmer days and nights could help to explain geographical variation in birth season for this species. Furthermore, climate change might shift the modal birth season at cool sites from spring to the preceding autumn, with loss of offspring mass in utero over warm winters also potentially favouring a shift in birth season over time.

中文翻译：

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壁虎活着的时候，更大的晒太阳机会和怀孕后期的温暖夜晚可以促进模态出生季节的发生，从而降低胚胎状况降低的风险

怀孕期间的高温状况会影响胎生蜥蜴的妊娠时间和后代表型。但是，过去的研究通常使女性在整个怀孕期间都接受晒太阳的治疗，这意味着人们对怀孕后期（包括分娩的暗示）或夜间温度所特有的影响知之甚少。我们研究了胚胎后期发育期间热处理对Woodworthia的影响'Otago / Southland'，一种胎生的壁虎，具有每年或每两年繁殖的异常能力。在凉爽气候，每两年繁殖一次的女性中，夏末的晒太阳机会和夜间温度升高，共同增加了实验室冬季前出生的比例。冬季之前出生的后代也比冬季之后出生的人具有更高的体重和身体状况。无论哪个季节，分娩前不久雌性的白天体温都会下降（可能有助于子宫内成熟胚胎的存活）），然后在分娩后立即增加以匹配新生儿。总体而言，昼夜变暖的综合影响可能有助于解释该物种出生季节的地理差异。此外，气候变化可能会将春季的模范出生季节从春季转移到前一个秋天，随着温暖的冬季子宫内后代质量的损失也可能会促使出生季节随时间推移而发生变化。