OPTIMIZING GREAT TIT CLUTCH SIZE IN A FLUCTUATING ENVIRONMENT
OPTIMIZING GREAT TIT CLUTCH SIZE IN A FLUCTUATING ENVIRONMENT
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DOI：
10.2307/1938814
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发表时间：
1987-02-01
期刊：
影响因子：
4.8
通讯作者：
PERRINS, CM
中科院分区：
文献类型：
--
作者：
BOYCE, MS;PERRINS, CM
大山雀（Parus major）在英国牛津附近的怀瑟姆森林筑巢，平均每窝产8.53个蛋，但最多产的窝数是12个。我们评估了各种机制，已建议解释这种明显的差异，包括（1）繁殖成本，（2）芒福德的“悬崖边缘效应”，（3）逐年环境变化。数据4489离合器，包括603操纵离合器，从过去的24年，提供弱或矛盾的支持前两个机制。有显着的年度环境波动，和相对健身的几何平均估计最好的预测所观察到的平均窝卵数。年轻人的生存状况不佳的年份对大离合器的影响要比对小离合器的影响大得多。这种“坏年效应”降低了平均值，增加了个体的适应性方差，这些个体在大窝时的适应性比在小窝时的适应性要高。因此，从长远来看，鸟的窝数小于最具生产力的窝数是更有利的。繁殖的成本，因为它影响成年人的生存是既不必要，也不充分的窝卵数优化在大山雀。
Great Tits (Parus major) nesting in Wytham Wood near Oxford, England, lay clutches averaging 8.53 eggs, although the most productive clutch size is 12. We evaluated various mechanisms that have been suggested to account for this apparent disparity, including (1) cost of reproduction, (2) Mountford''s "cliff-edge effect", and (3) year-to-year environmental variability. Data on 4489 clutches, including 603 manipulated clutches, from the past 24 yr, offer weak or contradictory support for the first two mechanisms. There are marked annual environmental fluctuations, and a geometric mean estimate of relative fitness best predicts the observed mean clutch size. Years that are poor for survival of young affect individuals laying larger clutches much more than they affect those laying smaller clutches. This "bad-years effect" reduces the mean and increases the variance in fitness for individuals laying large clutches more than it does for individuals laying smaller clutches. Hence it is more advantageous, in the long term, for birds to lay clutches smaller than the most productive clutch size. The cost of reproduction as it affects adult survival is neither necessary nor sufficient for clutch size optimization in Great Tits.