Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, Zurich CH-8057, Switzerland.
Kalahari Research Centre, Kuruman River Reserve, Van Zylsrus 8467, South Africa.
Biol Lett. 2023 Jun;19(6):20230183. doi: 10.1098/rsbl.2023.0183. Epub 2023 Jun 28.
In the majority of mammals, gestation length is relatively consistent and seldom varies by more than 3%. In a few species, females can adjust gestation length by delaying the development of the embryo after implantation. Delays in embryonic development allow females to defer the rising energetic costs of gestation when conditions are unfavourable, reducing the risk of embryo loss. Dispersal in mammals that breed cooperatively is a period when food intake is likely to be suppressed and stress levels are likely to be high. Here, we show that pregnant dispersing meerkats (), which have been aggressively evicted from their natal group and experience weight loss and extended periods of social stress, prolong their gestation by means of delayed embryonic development. Repeated ultrasound scans of wild, unanaesthetized females throughout their pregnancies showed that pregnancies of dispersers were on average 6.3% longer and more variable in length (52-65 days) than those of residents (54-56 days). The variation in dispersers shows that, unlike most mammals, meerkats can adapt to stress by adjusting their pregnancy length by up to 25%. By doing so, they potentially rearrange the costs of gestation during adverse conditions of dispersal and enhance offspring survival.
在大多数哺乳动物中，妊娠期相对稳定，很少有超过 3%的变化。在少数物种中，雌性可以通过在着床后延迟胚胎发育来调整妊娠期。胚胎发育的延迟使雌性能够在环境不利时推迟妊娠的能量成本上升，降低胚胎丢失的风险。在合作繁殖的哺乳动物中，扩散是一个食物摄入可能受到抑制且压力水平可能很高的时期。在这里，我们表明，被从其出生地群体中强烈驱逐且经历体重减轻和延长社交压力的怀孕的散居猫鼬（），通过延迟胚胎发育来延长其妊娠期。对野生未麻醉雌性在整个怀孕期间进行的多次超声扫描表明，散居者的妊娠平均比居民（54-56 天）长 6.3%，且长度变化更大（52-65 天）。散居者的变异表明，与大多数哺乳动物不同，猫鼬可以通过调整其妊娠长度来适应压力，最长可达 25%。通过这样做，它们可以在扩散的不利条件下重新安排妊娠成本，并提高后代的存活率。
