Life history theory predicts that there should be an inverse relationship between offspring size and number, because individuals cannot simultaneously maximize both when resources are limited. Although extensively studied in avian species, the occurrence and determinants of reproductive tradeoffs in oviparous reptiles are far less understood, particularly in parthenogenetic species. We studied this trade-off in the Colorado Checkered Whiptail, Aspidoscelis neotesselatus, a female-only parthenogenetic lizard. Using data previously collected in 2018 and 2019, we tested for clutch and egg size trade-offs and determined whether this relationship could be influenced by female size and aspects of physiological condition. Physiological condition included energy-mobilizing hormone (i.e. corticosterone ‘CORT’), oxidative stress (i.e. reactive oxygen metabolites ‘ROMs’), and innate immune function (bacterial killing ability ‘BKA’). We found the effect of clutch size on follicle size was significant, but not linear. Specifically, follicle size was on average larger in females with clutches of two follicles when compared to clutches of one follicle, but smaller in females with clutches of three when compared to clutches of two. In addition, females that were larger produced larger follicles regardless of clutch size. Neither CORT nor BKA affected the relationship between follicle size and clutch size. However, ROMs did explain variability in this relationship: oxidative stress was more elevated in females that produced larger clutches and larger follicles. We conclude that clutch size and body size are key life history traits that shape follicle size, and that investments into larger clutches and follicle size come at the cost of oxidative damage.

生活史理论预测后代大小和数量之间应该存在反比关系，因为当资源有限时，个体不能同时最大化两者。尽管在鸟类物种中进行了广泛的研究，但对卵生爬行动物的生殖权衡的发生和决定因素知之甚少，尤其是在孤雌生殖物种中。我们在科罗拉多方格鞭尾鱼 Aspidoscelis neotesselatus 中研究了这种权衡，一只雌性孤雌生殖蜥蜴。使用先前在 2018 年和 2019 年收集的数据，我们测试了离合器和鸡蛋大小的权衡，并确定了这种关系是否会受到雌性体型和生理状况方面的影响。生理状况包括能量动员激素（即皮质酮'CORT'）、氧化应激（即活性氧代谢物'ROMs'）和先天免疫功能（细菌杀伤能力'BKA'）。我们发现离合器大小对卵泡大小的影响是显着的，但不是线性的。具体来说，与拥有一个卵泡的离合器相比，拥有两个卵泡的雌性的卵泡大小平均更大，但与拥有两个卵泡的雌性相比，拥有三个卵泡的雌性的卵泡尺寸较小。此外，无论离合器大小如何，较大的雌性都会产生较大的卵泡。CORT 和 BKA 都不影响卵泡大小和离合器大小之间的关系。然而，ROM 确实解释了这种关系的可变性：在产生更大离合器和更大卵泡的雌性中氧化应激更高。我们得出结论，离合器大小和身体大小是影响卵泡大小的关键生活史特征，而对更大的离合器和卵泡大小的投资是以氧化损伤为代价的。