Combined spatial and tidal processes identify links between pelagic prey species and seabirds
Combined spatial and tidal processes identify links between pelagic prey species and seabirds
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DOI：
10.3354/meps10176
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发表时间：
2013-01-01
影响因子：
2.5
通讯作者：
Camphuysen, C. J.
中科院分区：
文献类型：
--
作者：
Cox, S. L.;Scott, B. E.;Camphuysen, C. J.
为了进一步了解捕食者物种的觅食行为，有必要更好地了解捕食者、猎物和周围环境之间的相互作用。本研究的主要目的是确定驱动海鸟觅食时间和地点变化的潜在过程，包括物理和生物过程。利用在北海福斯湾海域进行的一次海上调查中收集的海鸟丰度、猎物密度和海洋学变异性的精细同时测量数据，应用零膨胀负二项模型来确定驱动两种海鸟（普通海鸠Uria alge和黑腿三趾鸥Rissa tridactyla）觅食行为的潜在过程。海鸠模型和三趾鸥模型的结果都显示出一致性；特定的潮汐状态和热分层水平解释了观测到的丰度增加。这项研究的第二个目的是确定驱动猎物密度变化的关键海洋过程，并确定这些过程是否与海鸟觅食行为的潜在过程相比较。利用广义最小二乘法对猎物密度NASC-40-50（MAX）和NASC-50-70（MAX）的对数变换进行建模。类似的潮汐条件和热分层水平解释了分布模式，表明这些过程增加了猎物的可用性，为捕食者创造了有利可图的觅食机会。这被称为潮汐耦合假说，并指出关键的海洋生境不仅出现在有限的空间位置，而且出现在与潮汐循环有关的特定时间间隔内。此外，通过结合海洋对觅食栖息地的影响，还确定了精细尺度的捕食者-猎物关系。觅食海鸠和三趾鸥对NASC-40-50（MAX）值的升高表现为II型功能反应。
To gain further insight into the foraging behaviour of predator species, it is essential that interactions between predators, their prey and the surrounding environment are better understood. The primary purpose of this study was to determine the underlying processes, both physical and biological, driving variation in the times and locations of seabird foraging events. Using fine-scale simultaneous measurements of seabird abundance, prey density and oceanographic variability collected during an at-sea survey in the Firth of Forth region of the North Sea, zero-inflated negative binomial models were applied to identify the underlying processes driving foraging behaviour in 2 seabird species: the common guillemot Uria aalge and the black-legged kittiwake Rissa tridactyla. Both guillemot and kittiwake models showed consistency in their results; specific tidal states and thermal stratification levels explained observed increases in abundance. The secondary purpose of this study was to identify key oceanographic processes driving variability in prey density and determine if these were comparable to those underlying the behaviour of foraging seabirds. Log-transformations of 2 measures of prey density, NASC-40-50(MAX) and NASC-50-70(MAX), were modelled using generalised least squares. Similar tidal conditions and thermal stratification levels explained distributional patterns, suggesting that these processes act to increase prey availability, creating profitable foraging opportunities for predators to exploit. This has been termed the tidal coupling hypothesis and identifies that critical marine habitats occur not only at limited spatial locations but also within specific temporal intervals relating to the tidal cycle. Further more, by incorporating this oceanographic influence on foraging habitat, fine-scale predator-prey relationships were also identified. Foraging guillemots and kittiwakes displayed a Type II functional response to increasing values of NASC-40-50(MAX).