Fitness consequences of timing of migration and breeding in cormorants.
Fitness consequences of timing of migration and breeding in cormorants.
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DOI：
10.1371/journal.pone.0046165
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Bregnballe T
中科院分区：
文献类型：
--
作者：
Gienapp P;Bregnballe T
在大多数鸟类中，繁殖的时机影响繁殖的成功，因此早期繁殖是有利的。在迁徙物种的迁徙时间，特别是到达繁殖地的时间，与繁殖时间预期是相关的。因此，迁移时间也应该有健身的后果。然而，与繁殖时间相比，迁移时间的健身后果的证据要有限得多。气候变化已被证明会对营养水平之间的同步性产生负面影响，从而导致对时间的定向选择，但再次在鸟类迁徙时间的直接证据是稀缺的。在这里，我们分析了健身的后果，在大鸬鹚的迁移和繁殖时间，并测试是否气候变化导致增加选择的时间，使用一个长期的数据集，从一个繁殖殖民地的Vorsouth岛（丹麦）。繁殖成功率，衡量幼鸟的数量，与繁殖时间和到达时间在殖民地和下降的季节。这种季节性下降在研究期间的迁移和繁殖时间变得更加陡峭，并与冬季/春季气候呈正相关，即温暖的冬季/春季后选择更强。然而，增加选择压力的时间似乎是无关的气候变化的气候变量相关的选择强度并没有增加在研究期间。有间接证据表明，物候或丰富的首选猎物物种已经改变，这可能改变了选择的时间迁移和繁殖。
In most bird species timing of breeding affects reproductive success whereby early breeding is favoured. In migratory species migration time, especially arrival at the breeding grounds, and breeding time are expected to be correlated. Consequently, migration time should also have fitness consequences. However, in contrast to breeding time, evidence for fitness consequences of migration time is much more limited. Climate change has been shown to negatively affect the synchrony between trophic levels thereby leading to directional selection on timing but again direct evidence in avian migration time is scarce. We here analysed fitness consequences of migration and breeding time in great cormorants and tested whether climate change has led to increased selection on timing using a long-term data set from a breeding colony on the island of Vorsø (Denmark). Reproductive success, measured as number of fledglings, correlated with breeding time and arrival time at the colony and declined during the season. This seasonal decline became steeper during the study period for both migration and breeding time and was positively correlated to winter/spring climate, i.e. selection was stronger after warmer winters/springs. However, the increasing selection pressure on timing seems to be unrelated to climate change as the climatic variables that were related to selection strength did not increase during the study period. There is indirect evidence that phenology or abundances of preferred prey species have changed which could have altered selection on timing of migration and breeding.