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Great white sharks are afraid of orcas, study finds

研究发现,大白鲨惧怕虎鲸

By Madeline Farber | Fox News
It appears one of the most fear-inducing predators inthe ocean may have a fear of its own.

作为海洋中最令人恐惧的掠食者之一,可能也有自己的恐惧。



More specifically, researchers determined when both sharksand orcas were present at the Farallon Islands by comparing data from theelectronic shark tags with “field observations of orca sightings.”

更具体地说,研究人员通过比较电子鲨鱼标签上的数据和“虎鲸目视实地观察”,确定了在法拉隆群岛同时出现鲨鱼和虎鲸的时间。

“This made it possible to demonstrate the outcome on therare instances when the predators encountered each other,” per the study.

这项研究称:“这使得展示罕见的捕食者彼此相遇的后果成为可能。”

The “robust data sources” helped scientists to “conclusivelyshow how white sharks clear out of the area when the orcas show up,” Jim Tietz,a study co-author, said in an online statement.

该研究的合作者吉姆·蒂茨在一份线上声明中表示,这些“可靠的数据来源”帮助科学家“明确了当虎鲸出现时,大白鲨是如何离开该区域的”。

The sharks fled the island when the orcas arrived — and didnot return until the following season — in all of the cases studied. Datafrom the electronic tags even showed all the great white sharks left the areajust minutes after orcas arrived. This was true even when the killer whaleswere present for less than an hour.

在所有的研究案例中,鲨鱼都是在虎鲸到达时逃离该岛的,而且直到下一季才会回来。电子标签上的数据甚至显示,所有大白鲨在虎鲸到达后几分钟就离开了这个区域。即使虎鲸只待上不到一个小时,情况也是如此。

"On average we document around 40 elephant sealpredation events by white sharks at Southeast Farallon Island eachseason," Monterey Bay Aquarium scientist Scot Anderson said in astatement. "After orcas show up, we don't see a single shark and there areno more kills."

蒙特利湾水族馆的科学家斯科特·安德森在一份声明中说:“每一季,我们都会记录下法拉隆岛东南部海域大白鲨对象海豹的捕食事件,平均有约40起。虎鲸出现后,我们再没有看到一条鲨鱼,也没有鲨鱼的捕杀记录了。”



Sharks hightailing out of the area had an indirect benefitfor elephant seals — which are often the preferred meal of both sharks and killerwhales — in the Farallones. Researchers found there were “four to seven timesfewer predation events on elephant seals in the years white sharks left,” perthe study.

鲨鱼从这一地区被赶走对象海豹有间接的好处,在法拉隆,象海豹通常是鲨鱼和虎鲸的首选食物。研究人员发现,“在大白鲨离开的年份里,对象海豹的捕食事件减少了四到七倍。”

"We don't typically think about how fear and riskaversion might play a role in shaping where large predators hunt and how thatinfluences ocean ecosystems,” added Salvador Jorgensen, the study’s leadauthor. “It turns out these risk effects are very strong even for largepredators like white sharks — strong enough to redirect their hunting activityto less preferred but safer areas."

该研究的第一作者萨尔瓦多·乔根森补充说:“我们通常不会考虑恐惧和风险规避如何影响大型掠食者的捕猎地点,以及对海洋生态系统的影响。事实证明,即使对像大白鲨这样的大型掠食者来说,风险意识也是非常强烈的——强大到足以将它们的捕猎活动转向它们不太喜欢但更安全的地区。”

Jorgensen explained the study is important because it is oneof the few that "demonstrates how food chains are not always linear,"especially in the ocean. Interactions between predators are more difficultto document and analyze due to their infrequency.

乔根森解释说,这项研究很重要,因为它是少数几个“证明食物链并非总是线性的”研究之一,尤其是在海洋中。由于捕食者之间的互动并不频繁,记录和分析它们之间的互动是很困难的。