To lighten things up, one pretended to be Poseidon by placing a seaweed garland on his head and then throwing it into the ocean.

為了讓氣氛活絡，其中一個人假裝成波賽頓，將海草環放在頭上，然後扔進海裡。

Moments later, a dolphin surfaced with the seaweed crowning her head.

不久後，一隻海豚浮出水面，頭上戴著海草環。

Sure, this could have been a coincidence, but it's also entirely possible that the dolphin was mimicking the scientist.

當然，這可能是巧合，但也完全有可能是海豚在模仿科學家的行為。

That's because dolphins are one of the smartest animal species on Earth.

這是因為海豚是地球上最聰明的動物物種之一。

So exactly how smart are they?

那麼牠們到底有多聰明呢？

Like whales and porpoises, dolphins belong to the group of aquatic mammals known as cetaceans who comprise 86 different species and share a common link with ungulates, or hoofed animals.

像鯨魚和鼠海豚一樣，海豚屬於水生哺乳動物，稱為鯨豚，包括 86 種不同的物種，與有蹄類或有蹄動物有共同之處。

Originally land mammals, the first cetaceans entered the water about 55 million years ago as large predators with sharp teeth.

早期的陸地哺乳類，第一個鯨豚類在五千五百萬年前進入水中，伴隨著銳利牙齒成為巨大掠食者。

Then, a shift in ocean temperatures about 35 million years ago reduced the availability of prey.

之後在三千五百萬年前，海洋溫度改變，減少了捕食獵物的可能性。

One group of cetaceans who survived this disruption, the odontocetes, wound up smaller with less sharp teeth,

在這場生態劇變中倖存下來的鯨豚類動物，齒鯨體型變小且牙齒變得不再銳利，

but also larger and more complex brains that allowed for complex social relationships, as well as echolocation to navigate and communicate.

但同時也演化出較大且更複雜的腦部，進而衍伸出複雜的社會關係，並運用回聲原理來航行和溝通。

Jump ahead to the present, and modern dolphins' brains are so large that their encephalization quotient, their brain size compared to the average for their body size, is second only to humans.

回歸到現在，現代海豚的大腦很龐大，牠們的腦化指數也就是大腦和標準身體的比例僅次於人類。

Dolphins have evolved to survive through their ability to form complex social networks that hunt, ward off rivals, and raise offspring together.

海豚透過發展複雜的社會網絡來存活，不管是獵捕、避開敵人、或者增加後代子孫，皆是一起行動。

For example, one group of Florida dolphins practices a sophisticated form of cooperation to hunt fish.

舉例來說：一群佛羅里達的海豚，運行一套複雜的合作形式來捕捉魚群，

A dolphin designated as "the net-maker" kicks up mud while another gives the signal for the other dolphins to simultaneously line up and catch the escaping fish.

一隻海豚被任命為「網子製造者」，踢起泥巴，另一隻給予夥伴暗號， 同時其他的海豚排列組隊，捕捉逃跑的魚群。

Achieving a goal like this requires deliberate planning and cooperation, which, in turn, requires some form of intentional communication.

要完成這項任務，需要深思熟慮的計畫和合作，反過來說，這需要意圖溝通能力。

Dolphins pass down their communication methods and other skills from generation to generation.

海豚將這些溝通技巧和其他技能傳授給每一代的子孫。

Different dolphin populations exhibit variations in greetings, hunting strategies, and other behaviors.

不同的海豚族群展現不同的問候方式、獵捕策略，以及其他行為。

This sort of cultural transmission even extends to tool use.

這樣類似文化傳播，甚至發展到器具上的使用。

One group of bottlenose dolphins off the Australian coast, nicknamed The Dolphin Sponge Club,

一群寬吻海豚在澳洲海岸被稱做「海綿社海豚」，

has learned how to cover their rostrums with sponges when rooting in sharp corals, passing the knowledge from mother to daughter.

牠們學會在銳利珊瑚群中定居時，如何運用海綿蓋住嘴巴以達保護效果，這套智慧由母親傳授給女兒。

Dolphins have even demonstrated language comprehension.

海豚甚至展現出理解語文的能力，

When taught a language based on whistles and hand gestures, they not only understood what the signals meant, but that their order had meaning:

當我們用哨子和手勢來教導牠們基本語言，海豚不僅僅知道這些暗號的意思， 甚至知道這些順序是有意義的：

the difference between bringing the ball to the hoop and bringing the hoop to the ball.

將球帶到呼拉圈，或將呼拉圈帶到球旁邊有不一樣的指令。

So they were able to process two of the main elements of human language: symbols that stand for objects and actions, and syntax that governs how they are structured.

所以海豚可以發展出兩套人類語言的主要元素，代號表示物品和行動，排列方式決定如何組織起來。

Dolphins are also one of the few species who pass the mirror test.

海豚也是些許的物種中，通過鏡子測試之一，

By recognizing themselves in mirrors, they indicate physical self-awareness, and research shows they can recognize not just their bodies, but also other dolphins they know.

透過鏡子中認識自己，牠們顯示出身體自我意識，研究指出海豚不僅能認得自己的身體也能了解自我的想法，我們稱之為元認知。

In one study, dolphins compared two sounds and could indicate a same, different, or uncertain response.

有一項實驗，海豚分辨兩種聲音，可以指出是一樣的、不同的、或不確定的回答，

Just like humans, they indicated uncertainty more often with difficult trials, suggesting they are aware of what they know and how confident they feel about that knowledge.

就跟人類一樣，它們在許多困難的試驗指出不確定的答案， 告訴我們牠們了解牠們所知道的， 以及牠們對自己所擁有的知識感到自信。

But some of the most amazing things about dolphins are their senses of empathy, altruism, and attachment.

但其中最令人驚艷的是，海豚擁有同情心、利他主義，以及忠誠。

The habit of helping injured individuals extends across the species barrier, as evidenced by the many accounts of dolphins carrying humans to the surface to breathe.

牠們跨越物種障礙，幫助其他受傷的個體，很多證據顯示，海豚搬運溺水的人類回到海面上呼吸。

And like us, dolphins mourn their dead.

跟人一樣，海豚會哀悼死去的夥伴。

When we consider all the evidence, we may wonder why humans still hunt dolphins for meat, endanger them through fishing and pollution, or imprison them to perform tricks.

當我們思考這些跡象，可能會覺得為何人類仍要獵殺海豚當食物，過度釣魚和汙染危及海豚的生存，或者拘禁牠們當作表演工具。

The ultimate question may not be whether dolphins are intelligent and complex beings, but whether humans can empathize with them enough to keep them safe and free.

最終的問題不是在於海豚是否聰明，是否為複雜的生物，而是在於人類能否給予同情心並保護牠們的安全和自由。