Frontal zones, temperature gradient and depth characterize the foraging habitat of king penguins at South Georgia
Frontal zones, temperature gradient and depth characterize the foraging habitat of king penguins at South Georgia
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锋区、温度梯度和深度是南乔治亚岛王企鹅觅食栖息地的特征
DOI：
10.3354/meps09884
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发表时间：
2012
影响因子：
2.5
通讯作者：
P. Trathan
中科院分区：
文献类型：
--
作者：
Annette Scheffer;C. Bost;P. Trathan
研究海洋捕食者对海洋结构的反应对于了解它们的觅食行为和繁殖成功至关重要。利用全球定位系统(GPS)和时间-深度-温度-记录器(TDR)标签，我们调查了在南乔治亚州繁殖的王企鹅如何在水平和垂直维度上探索它们在夏季海面上的觅食区域。我们确定了水平栖息地的使用可能如何与不同的南极绕极流(ACC)锋面带和相关的水柱热结构有关。为了研究企鹅对水柱的利用，我们考察了由温度、温度梯度和深度定义的老化生态位，并探索了这些热特性对猎物追逐的重要性。王企鹅在孵化期间在极锋(PF)及其南缘觅食，在孵化期间在南极带(AAZ)和南极区前锋(SACCF)觅食。随着夏季的推进，觅食生态位变得更加明显，其特征是AAZ浅层温度梯度较强，SACCF较深层温度梯度较弱。这些生态位表明在AAZ的亚温跃层冬季水(WW)以及在SACCF的WW深水和环极深水(CDW)中觅食。南乔治亚州以北地区不同的行政协调委员会前锋区的影响似乎提供了一个水平和垂直隔离的环境。靠近蜂群的可选觅食区域和壁龛的存在显然对这些王企鹅的觅食成功起到了重要作用。
Investigating the responses of marine predators to oceanographic structures is of key importance for understanding their foraging behaviour and reproductive success. Using Global Positioning System (GPS) and Time-Depth-Temperature-Recorder (TDR) tags, we investigated how king penguins breeding at South Georgia explore their foraging area over the summer sea- son in both the horizontal and vertical dimensions. We determined how horizontal habitat use may relate to different Antarctic Circumpolar Current (ACC) frontal zones and associated thermal structuring of the water column. To study the penguins' use of the water column, we examined for- aging niches defined by temperature, temperature gradient and depth, and explored the impor- tance of these thermal properties for prey pursuit. King penguins foraged within the Polar Front (PF) and its southern edges during incubation, and the Antarctic Zone (AAZ) and Southern ACC Front (SACCF) during brooding. Foraging niches became more distinct with the advancing sum- mer season, defined by strong thermal gradients at shallow depths in the AAZ, and weak gradi- ents at greater depths in the SACCF. These niches indicate foraging in the sub-thermocline Winter Water (WW) in the AAZ, and in deep WW and Circumpolar Deep Water (CDW) at the SACCF. The influence of different ACC frontal zones in the area to the north of South Georgia appears to provide for a horizontally and vertically segregated environment. The presence of optional foraging areas and niches close to the colony clearly play an important role in these king penguins' foraging success.