關(guān)于虎鯨的5個令人驚訝的事實(shí)

關(guān)于虎鯨的5個令人驚訝的事實(shí)

1. Orcas aren't whales.

虎鯨不是鯨魚。

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

虎鯨通常被稱為逆戟鯨——它們確實(shí)像鯨魚一樣巨大——但它們實(shí)際上是世界上最大的海豚物種。

Photo: Alessandro De Maddalena/Shutterstock

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

虎鯨是目前已知的唯一一種以文化為基礎(chǔ)進(jìn)化而來的非人類動物。

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

在最近的一項研究中，研究人員分析了不同虎鯨的基因，發(fā)現(xiàn)基因的差異與文化的差異相一致。

"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."

富特的團(tuán)隊研究了太平洋中兩種虎鯨和南極海洋中三種虎鯨的基因組。我們在6月初的報告中說:“這些基因組被明確地分為5個不同的組，恰好與文化差異完全吻合。”“這些不同的群體很難融合在一起;他們捕獵不同的獵物，有不同的技術(shù)，甚至有不同的語言。所以它們也很少繁殖，這最終導(dǎo)致了不同的基因組。”

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

只有人類是根據(jù)文化進(jìn)化的，所以這對虎鯨來說是件大事，對科學(xué)來說也是。

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

逆戟鯨是地球上僅有的五種經(jīng)歷更年期的動物之一。

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:

所有其他動物在死亡前都有繼續(xù)繁殖的能力，但是逆戟鯨、人類、短鰭領(lǐng)航鯨、獨(dú)角鯨和白鯨在某一時刻停止了繁殖，并繼續(xù)存活了幾十年。為什么一個物種會進(jìn)化到中年停止繁殖?國家地理雜志分享了一個理論:

"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."

最令人信服的解釋之一是祖母假說。該法案于1966年提出，建議年齡較大的女性放棄生育更多孩子的選擇，這樣她們就能養(yǎng)活現(xiàn)有的孩子。通過幫助他們的子女和孫輩生存和發(fā)展，他們?nèi)匀淮_保他們的基因代代相傳。”

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.

但是關(guān)于絕經(jīng)的原因還有更多的問題。因為在整個成年期，兒子和女兒都留在圓莢體中，年長的女性與圓莢體中的每個人的聯(lián)系越來越密切。因為她和這么多的圓莢體成員共享基因，這是一個停止繁殖的好理由，取而代之的是專注于支持、指導(dǎo)和教育她的孩子、孫子和曾孫。

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

虎鯨群體被分成豆莢、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間的區(qū)別是基于語言的。一個氏族由幾個豆莢或家庭群體組成。所有的豆莢都說同樣的語言，但每個豆莢都有自己的口音。這很像說英語的人可能有倫敦腔、米德蘭腔或西部鄉(xiāng)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.

與此同時，氏族說著完全不同的語言。部落們聚在一起聊天，就像說英語的人、說俄語的人和說漢語的人試圖交談一樣。

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

社區(qū)是由經(jīng)常交叉的路徑或有重疊領(lǐng)土的部落組成的。

5. Orcas are the most widespread mammal besides humans.

逆戟鯨是除人類之外分布最廣的哺乳動物。

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).

這些物種分布在從北極到南極的各個地方，從北部和南部的冰冷水域到赤道附近的溫暖水域，包括夏威夷群島、加拉帕戈斯群島和加利福尼亞灣的周圍。在全球范圍內(nèi)，它們僅次于人類，或許也僅次于棕鼠(盡管人類可以把幫助棕鼠傳播的功勞歸于人類)。

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.

不僅世界上所有的海洋都發(fā)現(xiàn)了逆戟鯨，有時它們還出現(xiàn)在淡水河流中，包括萊茵河、泰晤士河和易北河。在哥倫比亞河上游100多英里的地方，人們甚至發(fā)現(xiàn)了一頭逆戟鯨在捕魚。