Drivers of age-specific survival in a long-lived seabird: contributions of observed and hidden sources of heterogeneity
Drivers of age-specific survival in a long-lived seabird: contributions of observed and hidden sources of heterogeneity
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DOI：
10.1111/j.1365-2656.2010.01784.x
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发表时间：
2011-03-01
影响因子：
4.8
通讯作者：
Pavard, Samuel
中科院分区：
文献类型：
--
作者：
Aubry, Lise M.;Cam, Emmanuelle;Pavard, Samuel
P>1。我们评估了招募年龄，动态生殖投资（特定时间的生殖状态）和脆弱性（未观察到的个体生存能力差异）对黑腿三趾鸥生存的相对影响。此外，我们还研究了观察到的生存轨迹的变异性是否可以通过即时生殖投资、累积投资或两者来最好地解释。推迟招募（>= 7岁）的个人比早期招募（3岁）的死亡风险更高，特别是在生命后期，这表明招募年龄可能是个人素质的一个指标。虽然招募年龄有助于解释存活率的变化，但随时间变化的生殖投资具有更大的影响。试图繁殖或不繁殖的二分法比其他生殖状态的参数化（如窝卵数、育雏数或繁殖成功率）更好地解释了生命中生存的变异性。在三趾鸥中，开始繁殖的条件是保持一个巢址，这被认为是一个非常有竞争力的活动。这也许可以解释为什么尝试繁殖是影响生存的关键投资水平，独立于结果（失败或成功）。有趣的是，一生中累积的生育尝试越多，死亡风险就越低，这表明育种经验也可能是父母质量的一个很好的指标。相比之下，试图在时间t繁殖增加了t和t + 1之间的死亡风险。因此，我们发现在试图繁殖和在这个种群中生存之间存在着直接的权衡;然而，越早招募的个体，他们积累的繁殖经验越多，成本就越小。最后，未观察到的异质性在个人之间的改善模型拟合（1中心点3倍）比固定和动态来源观察到的异质性在生殖投资，这表明它是至关重要的，以考虑到这两个来源的个体异质性研究生存轨迹。只有在同时考虑了异质性的两个来源后，我们才能够检测到生存的直接生殖投资的“成本”和累积育种尝试（经验）的“效益”，这是个体质量的代表。
P>1. We assessed the relative influence of variability in recruitment age, dynamic reproductive investment (time-specific reproductive states) and frailty (unobserved differences in survival abilities across individuals) on survival in the black-legged kittiwake. Furthermore, we examined whether observed variability in survival trajectories was best explained by immediate reproductive investment, cumulative investment, or both.2. Individuals that delayed recruitment (>= age 7) suffered a higher mortality risk than early recruits (age 3), especially later in life, suggesting that recruitment age may be an indicator of individual quality. Although recruitment age helped explain variation in survival, time-varying reproductive investment had a more substantial influence.3. The dichotomy of attempting to breed or not explained variability in survival across life better than other parameterizations of reproductive states such as clutch size, brood size or breeding success. In the kittiwake, the sinequanon condition to initiate reproduction is to hold a nest site, which is considered a very competitive activity. This might explain why attempting to breed is the key level of investment that affects survival, independent of the outcome (failure or success).4. Interestingly, the more individuals cumulate reproductive attempts over life, the lower their mortality risk, indicating that breeding experience may be a good indicator of parental quality as well. In contrast, attempting to breed at time t increased the risk of mortality between t and t + 1. We thus detected an immediate trade-off between attempting to breed and survival in this population; however, the earlier individuals recruited, and the more breeding experience they accumulated, the smaller the cost.5. Lastly, unobserved heterogeneity across individuals improved model fit more (1 center dot 3 times) than fixed and dynamic sources of observed heterogeneity in reproductive investment, demonstrating that it is critical to account for both sources of individual heterogeneity when studying survival trajectories. Only after simultaneously accounting for both sources of heterogeneity were we able to detect the 'cost' of immediate reproductive investment on survival and the 'benefit' of cumulative breeding attempts (experience), a proxy to individual quality.