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首页> 外文期刊>Marine ecology progress series >Changes in diet and maternal attendance of South American sea lions indicate changes in the marine environment and prey abundance
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Changes in diet and maternal attendance of South American sea lions indicate changes in the marine environment and prey abundance

机译：南美海狮饮食和产妇出勤率的变化表明海洋环境和猎物丰富度发生了变化

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Behavioural observations were made of South American sea lions Otaria flavescens in Peru to determine whether changes in their diet and maternal attendance patterns reflected physical changes in the marine environment and alterations in the abundance and distribution of prey. The study was conducted during the breeding season between 1998 and 2002, which was a period that encompassed a strong El Nino (1997 to 1998) and a moderate La Nina (1999 to 2001). Observations revealed strong linkages between maternal attendance patterns and the abundance of prey and oceanographic features close to the rookeries. Acute prey shortage during El Nino resulted in females increasing the length of their foraging trips and decreasing the time they spent onshore with their pups. In contrast, shorter times at sea and longer times onshore were observed during the favourable conditions of La Nina when preferred prey (anchovy and squat lobster) were more abundant near the rookeries. Pup mortalities increased when females spent more time at sea searching for prey and did not return frequently enough to nurse their pups. A larger diversity of prey species (particularly of demersal fishes) was consumed during El Nino when anchovy and lobster were less available. Females appeared to adjust their diets and maternal attendance patterns in response to annual changes in the abundance and distribution of prey. These observations suggested that diet and maternal responses reflect interannual fluctuations of the unpredictable Peruvian upwelling ecosystem, and implied that South American sea lions may be good indicators of relative changes in the distribution and abundance of marine resources.
机译：对秘鲁的南美海狮Otaria flavescens进行了行为观察，以确定它们的饮食和产妇出勤方式的变化是否反映了海洋环境的物理变化以及猎物的数量和分布的变化。这项研究是在1998年至2002年的繁殖季节进行的，该时期包括强壮的厄尔尼诺现象（1997年至1998年）和中度的拉尼娜现象（1999年至2001年）。观察结果表明，孕产妇出勤方式与靠近群居地的丰富猎物和海洋特征之间有很强的联系。在厄尔尼诺现象期间，猛烈的猎物短缺导致雌性增加了觅食旅行的时间，并减少了与幼犬一起在岸上度过的时间。相反，在拉尼娜（La Nina）的有利条件下，当群附近的首选猎物（鱼和蹲龙虾）更加丰富时，在海上观察到的时间较短，在陆地上观察到的时间更长。当雌性花更多的时间在海上寻找猎物并且没有经常回来照顾它们的幼崽时，幼崽的死亡率增加。在厄尔尼诺期间，由于缺乏vy鱼和龙虾，因此消耗了更多种类的猎物（尤其是海鱼）。雌性似乎根据其猎物的数量和分布的年度变化来调整饮食和产妇的出勤方式。这些观察结果表明，饮食和产妇反应反映了不可预测的秘鲁上升生态系统的年际波动，并暗示南美海狮可能是海洋资源分布和丰度相对变化的良好指标。

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