关于虎鲸的5个令人惊讶的事实

关于虎鲸的5个令人惊讶的事实

1. Orcas aren't whales.

虎鲸不是鲸鱼。

Orcas are often called killer whales — and they are indeed enormous like whales — but they're actually the world's largest species of dolphin.

虎鲸通常被称为逆戟鲸——它们确实像鲸鱼一样巨大——但它们实际上是世界上最大的海豚物种。

Photo: Alessandro De Maddalena/Shutterstock

2. Orcas are the only known non-human animal to have evolved based on culture.

虎鲸是目前已知的唯一一种以文化为基础进化而来的非人类动物。

In a recent study, the genes of different orca pods were analyzed, and researchers found that distinctions in genes coincided with distinctions in culture.

在最近的一项研究中，研究人员分析了不同虎鲸的基因，发现基因的差异与文化的差异相一致。

"Foote's team looked at the genomes of two killer whale cultures in the Pacific Ocean and three cultures in the Antarctic Ocean. The genomes were shown to clearly fall into five different groups, which just happened to coincide perfectly with the cultural distinctions," we reported in early June. "It's not easy for these distinct groups to mingle; they hunt different prey, have different techniques, and even have different languages. So they also rarely breed, which eventually leads to distinct genomes."

富特的团队研究了太平洋中两种虎鲸和南极海洋中三种虎鲸的基因组。我们在6月初的报告中说:“这些基因组被明确地分为5个不同的组，恰好与文化差异完全吻合。”“这些不同的群体很难融合在一起;他们捕猎不同的猎物，有不同的技术，甚至有不同的语言。所以它们也很少繁殖，这最终导致了不同的基因组。”

Only humans are known to have evolved based on culture, so this is a big deal for orcas — and for science.

只有人类是根据文化进化的，所以这对虎鲸来说是件大事，对科学来说也是。

3. Orcas are one of only 5 animal species on the planet to go through menopause.

逆戟鲸是地球上仅有的五种经历更年期的动物之一。

All other animals continue to have the ability to reproduce until their deaths, but orcas, humans, short-finned pilot whales, narwhals and belugas stop reproducing at a certain point, and continue to live on for many decades. Why would a species evolve to stop reproducing mid-life? National Geographic shares a theory:

所有其他动物在死亡前都有继续繁殖的能力，但是逆戟鲸、人类、短鳍领航鲸、独角鲸和白鲸在某一时刻停止了繁殖，并继续存活了几十年。为什么一个物种会进化到中年停止繁殖?国家地理杂志分享了一个理论:

"One of the most compelling explanations is called the grandmother hypothesis. Proposed in 1966, it suggests that older females forgo the option to bear more children so they can support their existing ones. By helping their children and grandchildren to survive and thrive, they still ensure that their genes cascade down the generations."

最令人信服的解释之一是祖母假说。该法案于1966年提出，建议年龄较大的女性放弃生育更多孩子的选择，这样她们就能养活现有的孩子。通过帮助他们的子女和孙辈生存和发展，他们仍然确保他们的基因代代相传。”

But there's more to this question of why menopause happens. Because both sons and daughters remain in the pod throughout adulthood, the older females are increasingly related to everyone in the pod. Because she shares genes with so many of her pod members, it's a good reason to stop breeding and instead focus on supporting, guiding and teaching her children, grandchildren and great grandchildren.

但是关于绝经的原因还有更多的问题。因为在整个成年期，儿子和女儿都留在圆荚体中，年长的女性与圆荚体中的每个人的联系越来越密切。因为她和这么多的圆荚体成员共享基因，这是一个停止繁殖的好理由，取而代之的是专注于支持、指导和教育她的孩子、孙子和曾孙。

4. Orca groups are divided into pods, clans and communities.

虎鲸群体被分成豆荚、氏族和群落。

The distinctions between different pods and clans are based on language. A single clan is comprised of several pods or family groups. All of the pods speak the same language, but each pod has its own accent. It's much like English speakers might have a Cockney, Midlands or West Country accent.

不同的部落和部落之间的区别是基于语言的。一个氏族由几个豆荚或家庭群体组成。所有的豆荚都说同样的语言，但每个豆荚都有自己的口音。这很像说英语的人可能有伦敦腔、米德兰腔或西部乡村口音。

Meanwhile, clans speak completely different languages. Clans coming together for a chat would be like an English speaker, Russian speaker and Chinese speaker trying to have a conversation.

与此同时，氏族说着完全不同的语言。部落们聚在一起聊天，就像说英语的人、说俄语的人和说汉语的人试图交谈一样。

Communities are made up of clans that regularly cross paths or have territories that overlap.

社区是由经常交叉的路径或有重叠领土的部落组成的。

5. Orcas are the most widespread mammal besides humans.

逆戟鲸是除人类之外分布最广的哺乳动物。

The species ranges from the Arctic to the Antarctic, and are found everywhere from the freezing waters of the north and south to the warm waters along the equator, including around the Hawaiian Islands, Galapagos and Gulf of California. They're second only to humans and perhaps the brown rat for global distribution (though humans can take credit for helping the brown rat's spread).

这些物种分布在从北极到南极的各个地方，从北部和南部的冰冷水域到赤道附近的温暖水域，包括夏威夷群岛、加拉帕戈斯群岛和加利福尼亚湾的周围。在全球范围内，它们仅次于人类，或许也仅次于棕鼠(尽管人类可以把帮助棕鼠传播的功劳归于人类)。

Not only have orcas been spotted in all of the world's oceans, but sometimes they have been spotted in freshwater rivers, including the Rhine, Thames and Elbe rivers. An orca was even spotted more than 100 miles up the Columbia River as it hunted fish.

不仅世界上所有的海洋都发现了逆戟鲸，有时它们还出现在淡水河流中，包括莱茵河、泰晤士河和易北河。在哥伦比亚河上游100多英里的地方，人们甚至发现了一头逆戟鲸在捕鱼。