...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>ICES Journal of Marine Science >Changes in diet and trophic position of a top predator 10 years after a mass mortality of a key prey
【24h】

Changes in diet and trophic position of a top predator 10 years after a mass mortality of a key prey

机译：重要猎物大规模死亡10年后顶级捕食者的饮食和营养位置的变化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

After the disappearance of primary prey, seabirds exhibit gradually decreased breeding performance, and eventually the population size drops. Results are presented of an investigation into the diet of little penguins (Eudyptula minor) at Phillip Island, Australia, during a period when their key prey, pilchard (Sardinops sagax), declined dramatically. Data from stomach flushing (1982-2006) were used, supported by stable isotope (δ~(15)N,δ~(13)C) analyses of blood samples (2003, 2004, and 2006). The effect of the pilchard mortality on penguin diet was immediate, the birds shifting to a diet almost devoid of pilchard, and this was followed by 2 years of low breeding success, with considerably fewer penguins coming ashore. During periods when pilchard was not part of the diet, penguins consumed prey of a higher trophic level, e.g. higher values of δ~(15)N. Variability in penguin blood δ~(15)N coincided with years of low prey diversity. The disappearance of pilchard resulted in a decrease in prey diversity and led penguins to "fish up" the foodweb, possibly because of the simplified trophic structure. After 1998, however, breeding success re-attained average levels and the numbers of penguins coming ashore increased, probably because of increased abundance of prey other than pilchard after a 3-year period of food scarcity. Although little penguins apparently compensated over time, a less-flexible diet could make them ultimately vulnerable to further changes in their foodweb.
机译：在主要猎物消失之后，海鸟的繁殖性能逐渐下降，最终种群数量下降。在澳大利亚的菲利普岛（Phillip Island）的小企鹅（沙丁鱼（Sardinops sagax））急剧下降的时期，对小企鹅的饮食进行了调查。在稳定同位素（δ〜（15）N，δ〜（13）C）分析血样（2003、2004和2006）的支持下，使用了从胃潮红（1982-2006）获得的数据。沙丁鱼死亡率对企鹅日粮的影响是立竿见影的，鸟类转变为几乎没有沙丁鱼的日粮，随后两年的繁殖成功率很低，上岸的企鹅大大减少。在不吃沙丁鱼的时期，企鹅消耗了较高营养水平的猎物，例如较高的δ〜（15）N值。企鹅血液δ〜（15）N的变异性与多年低猎物多样性相吻合。沙丁鱼的消失导致猎物多样性的下降，并导致企鹅“捞起”食物网，这可能是由于简化了营养结构。但是，在1998年之后，繁殖成功又恢复到平均水平，上岸的企鹅数量增加了，这可能是由于缺乏粮食3年后，除了沙丁鱼以外的其他猎物的数量增加了。尽管很少的企鹅显然会随着时间的流逝而得到补偿，但缺乏弹性的饮食可能会使它们最终容易受到食物网络进一步变化的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号