PREDICTORS OF JUVENILE SURVIVAL IN BIRDS
PREDICTORS OF JUVENILE SURVIVAL IN BIRDS
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DOI：
10.1525/om.2013.78.1.1
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发表时间：
2013-01-01
期刊：
影响因子：
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通讯作者：
Anderson, David J.
中科院分区：
文献类型：
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作者：
Maness, Terri J.;Anderson, David J.
鸟类在幼年期的生存概率，父母的照顾和成年期之间的结束，是高度可变的，并对人口动态和父母的健身有重大影响。因此，大量的研究试图评估鸟类幼仔存活的潜在预测因子，特别是与父母照顾有关的预测因子。缺乏的假设连接身体储备积累从父母的照顾天真的青少年的生存组织了大部分的研究，但各种其他预测也进行了调查，并得到了一些支持。我们回顾了这一领域的文献，并确定了各种方法的问题，模糊了身体的结果的解释。大多数研究采用的统计技术错过了以下机会：（1）评估几个预测因子的相对重要性，（2）控制预测变量之间相关性的混杂效应，（3）通过评估潜在预测因子对青少年生存的间接（通过相关性）和直接影响来利用共线性的信息内容。最后，我们得出结论，太少的可靠的研究存在，让任何假设的强有力的评估有关青少年生存的鸟类。我们使用路径分析来测试2,631个后代的7个年度队列的海鸟，纳斯卡鲣鸟（苏拉granti）的少年生存的潜在预测。雏鸟的年龄是幼鸟存活率最重要的预测因子：当所有其他变量保持不变时，快速生长的后代存活率最高。后代性别是下一个最重要的预测因素，少年男性（较小的性别）比女性生存得更好。孵化日，体重指数，翅长也表现出重要的预测能力，但队列大小，culmen长度，和离合器大小和孵化成功的指数没有。雏鸟的生长受到损害，在恶劣的饲养条件下：整体重量下降，所需的天数达到羽翼丰满的状态增加，和一些结构的增长，但不是其他的，减少。这些影响在雌性中更为明显，雌性较高的幼鱼死亡率解释了该种群中成年性别比及其伴随的“配偶轮换”交配系统中的大部分雄性偏见。以前的大多数研究并没有将性别作为青少年生存的潜在预测因素。如果我们在模型中忽略性别，我们会得出两个错误的结论：体重不会影响幼年的存活率，而小的结构尺寸会提高存活率。
The survival probability of birds during the juvenile period, between the end of parental care and adulthood, is highly variable and has a major effect on population dynamics and parental fitness. As such, a large number of studies have attempted to evaluate potential predictors of juvenile survival in birds, especially predictors related to parental care. Lack's hypothesis linking body reserves accumulated from parental care to the survival of naive juveniles has organized much of this research, but various other predictors have also been investigated and received some support. We reviewed the literature in this area and identified a variety of methodological problems that obscure interpretation of the body of results. Most studies adopted statistical techniques that missed the opportunities to (1) evaluate the relative importance of several predictors, (2) control the confounding effect of correlation among predictor variables, and (3) exploit the information content of collinearity by evaluating indirect (via correlation) as well as direct effects of potential predictors on juvenile survival. Ultimately, we concluded that too few reliable studies exist to allow robust evaluations of any hypothesis regarding juvenile survival in birds. We used path analysis to test potential predictors of juvenile survival of 2,631 offspring from seven annual cohorts of a seabird, the Nazca Booby (Sula granti). Fledging age was the most important predictor of juvenile survival: fast-growing offspring survived best, when all other variables were held constant. Offspring sex was the next most important predictor, with juvenile males (the smaller sex) surviving better than females. Hatching day, an index of body weight, and wing length also showed important predictive ability, but cohort size, culmen length, and an index of clutch size and hatching success did not. Nestling growth was compromised under poor rearing conditions: overall weight fell, the number of days needed to reach fledging status increased, and the growth of some structures, but not others, was reduced. These effects were more pronounced in females, and the higher juvenile mortality of females accounts for most of the male bias in the adult sex ratio and its attendant "mate rotation" mating system in this population. Most previous studies did riot evaluate sex as a potential predictor of juvenile survival. Had we omitted sex from our models, we would have made two erroneous conclusions: that weight did not influence juvenile survival, and that small structural size enhanced it.