Rivalan Philippe, Prévot-Julliard Anne-Caroline, Choquet Remi, Pradel Roger, Jacquemin Bertrand, Girondot Marc
Laboratoire Ecologie, Systématique et Evolution, UMR 8079, CNRS, ENGREF & Université Paris Sud, Bâtiment 362, 91405 Orsay cedex, France.
Oecologia. 2005 Oct;145(4):564-74. doi: 10.1007/s00442-005-0159-4. Epub 2005 Oct 13.
The trade-off between current and future reproduction plays an important role in demographic analyses. This can be revealed by the relationship between the number of years without reproduction and reproductive investment within a reproductive year. However, estimating both the duration between two successive breeding season and reproductive effort is often limited by variable recapture or resighting effort. Moreover, a supplementary difficulty is raised when nonbreeder individuals are not present sampling breeding grounds, and are therefore unobservable. We used capture-recapture (CR) models to investigate intermittent breeding and reproductive effort to test a putative physiological trade-off in a long-lived species with intermittent breeding, the leatherback sea turtle. We used CR data collected on breeding females on Awa:la-Ya:lima:po beach (French Guiana, South America) from 1995 to 2002. By adding specific constraints in multistate (MS) CR models incorporating several nonobservable states, we modelled the breeding cycle in leatherbacks and then estimated the reproductive effort according to the number of years elapsed since the last nesting season. Using this MS CR framework, the mean survival rate was estimated to 0.91 and the average resighting probability to 0.58 (ranged from 0.30 to 0.99). The breeding cycle was found to be limited to 3 years. These results therefore suggested that animals whose observed breeding intervals are greater than 3 years were most likely animals that escaped detection during their previous nesting season(s). CR data collected in 2001 and 2002 allowed us to compare the individual reproductive effort between females that skipped one breeding season and females that skipped two breeding seasons. These inferences led us to conclude that a trade-off between current and future reproduction exists in leatherbacks nesting in French Guiana, likely linked to the resource provisioning required to invest in reproduction.
当前繁殖与未来繁殖之间的权衡在人口统计学分析中起着重要作用。这可以通过非繁殖年限与繁殖年内繁殖投入之间的关系来揭示。然而，估计两个连续繁殖季节之间的持续时间和繁殖努力往往受到可变的重捕或重新观察努力的限制。此外，当非繁殖个体不在繁殖地采样时，会出现一个额外的困难，因此无法观察到它们。我们使用捕获-重捕（CR）模型来研究间歇性繁殖和繁殖努力，以测试一种具有间歇性繁殖的长寿物种——棱皮龟的假定生理权衡。我们使用了1995年至2002年在南美洲法属圭亚那阿瓦拉-亚利马波海滩收集的关于繁殖雌性棱皮龟的CR数据。通过在包含几个不可观察状态的多状态（MS）CR模型中添加特定约束，我们对棱皮龟的繁殖周期进行了建模，然后根据自上一个筑巢季节以来经过的年数估计繁殖努力。使用这个MS CR框架，平均存活率估计为0.91，平均重新观察概率为0.58（范围从0.30到0.99）。发现繁殖周期限制在3年。因此，这些结果表明，观察到的繁殖间隔大于3年的动物很可能是在前一个筑巢季节逃脱检测的动物。2001年和2002年收集的CR数据使我们能够比较跳过一个繁殖季节的雌性和跳过两个繁殖季节的雌性之间的个体繁殖努力。这些推断使我们得出结论，在法属圭亚那筑巢的棱皮龟中存在当前繁殖与未来繁殖之间的权衡，这可能与繁殖所需的资源供应有关。
