Segura Amalia, Rodriguez-Caro Roberto C, Graciá Eva, Acevedo Pelayo
Instituto de Investigación en Recursos Cinegéticos, IREC (CSIC-UCLM-JCCM), Ronda de Toledo, 12, 13071 Ciudad Real, Spain.
Applied Biology Department, Universidad Miguel Hernández, Avda. de la Universidad sn. Edificio Torreblanca, 03202 Elche, Spain.
Animals (Basel). 2021 Feb 10;11(2):467. doi: 10.3390/ani11020467.
Long-lived species are particularly interesting for investigation of trade-offs that shape reproductive allocation and the effective contribution to the next generations. Life history theory predicts that these species will buffer environmental stochasticity via changes in the reproductive investment, while maintaining high adult survival rates. The spur-thighed tortoise was selected as a case study in order to investigate the relationship between the linked maternal characteristics (size and age) and related traits in their hatchlings. We tracked naturally emerging hatchlings from young and old females under semi-natural conditions to test variations in hatchling numbers, body mass, size and survival over two years. We used linear mixed-effect models to analyze variations in hatchling body mass and size, and a mark-release-recapture framework to model their survival. Our study illustrates that old females of long-lived species have greater offspring numbers, greater survival and smaller size when compared with those of young females. The interannual variability evidenced the reduced offspring number and survival in the lower autumn rainfall and spring mean temperature year. Our results highlight the role of maternal age and climatic conditions in the population dynamics and the need for long-term studies of reproduction traits for designating adequate conservation strategies.
长寿物种对于研究影响繁殖分配和对下一代有效贡献的权衡取舍而言尤为有趣。生活史理论预测，这些物种将通过改变繁殖投入来缓冲环境随机性，同时保持较高的成年个体存活率。为了研究相关母体特征（体型和年龄）与其幼体相关性状之间的关系，我们选择了 spur-thighed 乌龟作为案例研究对象。我们在半自然条件下追踪了年轻和年老雌性乌龟自然孵化出的幼体，以测试两年内幼体数量、体重、体型和存活率的变化。我们使用线性混合效应模型来分析幼体体重和体型的变化，并使用标记重捕框架来模拟它们的存活率。我们的研究表明，与年轻雌性相比，长寿物种的年老雌性具有更多的后代数量、更高的存活率和更小的体型。年际变化表明，在秋季降雨量较低和春季平均温度较低的年份，后代数量和存活率会降低。我们的研究结果突出了母体年龄和气候条件在种群动态中的作用，以及为制定适当的保护策略而对繁殖性状进行长期研究的必要性。
