Climate change is generating range shifts in many organisms, notably along the elevational gradient in mountainous environments. However, moving up in elevation exposes organisms to lower oxygen availability, which may reduce the successful reproduction and development of oviparous organisms. To test this possibility in an upward‐colonizing species, we artificially incubated developing embryos of the viperine snake (Natrix maura) using a split‐clutch design, in conditions of extreme high elevation (hypoxia at 2877 m above sea level; 72% sea‐level equivalent O₂ availability) or low elevation (control group; i.e. normoxia at 436 m above sea level). Hatching success did not differ between the two treatments. Embryos developing at extreme high elevation had higher heart rates and hatched earlier, resulting in hatchlings that were smaller in body size and slower swimmers compared to their siblings incubated at lower elevation. Furthermore, post‐hatching reciprocal transplant of juveniles showed that snakes which developed at extreme high elevation, when transferred back to low elevation, did not recover full performance compared to their siblings from the low elevation incubation treatment. These results suggest that incubation at extreme high elevation, including the effects of hypoxia, will not prevent oviparous ectotherms from producing viable young, but may pose significant physiological challenges on developing offspring in ovo. These early‐life performance limitations imposed by extreme high elevation could have negative consequences on adult phenotypes, including on fitness‐related traits.

中文翻译：

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高海拔缺氧会影响潜在的山地定居者的围产期生理和性能。

气候变化正在引起许多生物的范围变化，特别是沿着山区环境中的海拔梯度变化。但是，升高海拔会使生物体的氧气利用率降低，这可能会降低卵生生物体的成功繁殖和发育。为了测试在向上定殖的物种这种可能性，我们人工孵育毒蛇蛇（的发育胚胎虎斑毛拉72％海基;在2877米海拔）使用分离式离合器设计，在极端高海拔（缺氧条件等效水平O ₂可用性）或低海拔（对照组；即海拔436 m的常氧）。两种处理之间的孵化成功率没有差异。与在较低海拔下孵化的兄弟姐妹相比，在极端较高海拔下发育的胚胎具有更高的心率和更早的孵化，从而导致幼体的体型较小，游泳者的速度也较慢。此外，孵化后的对等幼体移植表明，从低海拔孵化处理中移出至低海拔的蛇，在转移回低海拔的情况下，与其兄弟姐妹相比，不能恢复全部性能。这些结果表明，在极高的温度下进行孵化（包括缺氧的影响）不会阻止卵子的外温产生活的幼小，在ovo。这些极端高海拔所造成的早期生命表现方面的限制可能会对成年表型产生负面影响，包括与健身相关的性状。