Consequences of recruitment decisions and heterogeneity on age-specific breeding success in a long-lived seabird
Consequences of recruitment decisions and heterogeneity on age-specific breeding success in a long-lived seabird
复制标题
DOI：
10.1890/08-1475.1
复制
发表时间：
2009-09-01
期刊：
影响因子：
4.8
通讯作者：
Cam, Emmanuelle
中科院分区：
文献类型：
--
作者：
Aubry, Lise M.;Koons, David N.;Cam, Emmanuelle
个体首次繁殖的年龄以及在连续繁殖尝试中的投入涉及一些可能阻碍体细胞修复的机制，从而导致繁殖能力随年龄下降（繁殖衰老）。我们利用来自黑脚三趾鸥（一种长寿海鸟）的长期数据，在考虑繁殖经验和繁殖成功率（BS）的时间变化的同时，研究了加入繁殖群体的年龄、特定年龄的繁殖成功率以及繁殖衰老之间的关系。我们首先在所有加入繁殖群体中检测到繁殖后期繁殖成功率的提高，我们将其认定为“代内选择”或“脆弱”表型的选择性消失。当准确考虑到这种异质性时，我们发现所有个体都经历繁殖衰老。我们首先强调了不同加入繁殖群体在加入繁殖前后经验的不同组合如何导致在中间年龄达到最大繁殖成功率。早期加入繁殖的个体随着获得加入繁殖后的经验，其繁殖成功率提高，而晚期加入繁殖的个体因获得加入繁殖前的经验而在加入繁殖时就有较高的繁殖成功率。只有在中间年龄加入繁殖的个体平衡了其加入繁殖前后的经验。与“累积繁殖成本假说”一致，我们还观察到老年时早期加入繁殖的个体繁殖成功率下降得更快，而延迟加入繁殖的个体繁殖成功率随年龄下降得最慢。然而，严格来说，早期加入繁殖的个体在中间年龄（10 - 13岁）达到最高的繁殖成功率水平，而延迟加入繁殖的个体在相似年龄达到最低水平。这些不同的轨迹可能反映了一种“延迟权衡”，即在中年时繁殖成功率最大化与老年时繁殖衰老之间的平衡。此外，繁殖成功率的年度变化对生命早期的个体影响更大，这表明有经验的个体能够缓冲时间变化对繁殖成功率的影响，这最终可以提高在随机环境中的适应性。我们的研究结果强调：（1）在检测个体内部衰老时，观察到的和未观察到的异质性都很重要；（2）在长寿物种中，短期权衡可能很少见；因此，应将累积繁殖成本作为繁殖衰老背后的一种替代机制。
An individual's age at first reproduction and investment in successive reproductive attempts are involved in mechanisms that can impede somatic repair, resulting in a decline in reproductive abilities with age (reproductive senescence). We used long-term data from the Black-legged Kittiwake, a long-lived seabird, to address the relationship between recruitment age, age-specific breeding success (BS), and reproductive senescence, while accounting for breeding experience and temporal variation in BS. We first detected late-life improvement in BS across all recruitment groups, which we recognized as "within-generation selection'' or the selective disappearance of "frail'' phenotypes. When such heterogeneity was accurately accounted for, we showed that all individuals suffered reproductive senescence. We first highlighted how different combinations of pre- and post-recruitment experience across recruitment groups resulted in maximal BS at intermediate ages. BS increased in early recruits as they gained post-recruitment experience, whereas late recruits gained pre-recruitment experience that led to high BS at recruitment. Only individuals recruiting at intermediate ages balanced their pre- and post-recruitment experience. Consistent with the "cumulative reproductive cost hypothesis,'' we also observed a faster decline in BS in early recruits at advanced ages, whereas individuals delaying recruitment experienced the slowest decline in BS with age. Early recruits, however, reached the highest levels of BS at intermediate ages, sensus stricto (10-13 years old), whereas individuals delaying recruitment experienced the lowest at similar ages. These divergent trajectories may reflect a "delayed trade-off'' balancing a maximization of midlife BS against reproductive senescence at advanced ages. Additionally, annual variation in BS had a greater effect on individuals early in life, suggesting that experienced individuals were able to buffer out the effects of temporal variation on BS, which can ultimately improve fitness in stochastic environments. Our findings stress that (1) both observed and unobserved heterogeneity are important in detecting within-individual senescence, and (2) short-term trade-offs may be rare in long-lived species; thus, cumulated reproductive costs should be invoked as an alternative mechanism underlying reproductive senescence.