在岩石上晒太阳或海滩上蹒跚的海狮，很容易让人觉得它们更像是海洋家猫，但是，千万不要被它们在海滩上的行为所误导。海浪下，海狮是耐力惊人的猎手，时速达18英里，一次可以狩猎30小时。克莱尔·西蒙尼潜心研究了让这些巨大的哺乳动物变成足智多谋的觅食者的原因。
中英文对照字幕文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
Sunning themselves on rocks or waddling awkwardly across the beach, it’s easy to think of these immobile mammals less as sea lions, and more as sea house cats. But don’t be fooled by their beachside behavior. Under the waves, sea lions are incredible endurance hunters. Hurtling around at speeds from 4 to 18 miles an hour and hunting for up to 30 hours at a time, these majestic mammals live up to their name. And thanks to a suite of physical adaptations, finely tuned over millions of years, they make for resourceful foragers. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
岩石上晒着太阳或海滩上蹒跚的海狮，这些不能正常行走的哺乳动物容易让人觉得不像海狮，而是像家猫。但不要被它们在海滩上的行为所误导。海浪之下，海狮是耐力超强的猎手，它们时速可达4到18英里，一次狩猎可长达30个小时，这些了不起的哺乳动物绝对是实至名归。得益于一系列的身体适应变化，历经数百万年的细微调整，它们成为足智多谋的觅食者。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
To find their favorite food, sea lions hunt much deeper than many of their semi-aquatic peers. With some species diving to depths of nearly 400 meters, they’re able to cope with the mounting pressure by collapsing their pliable rib cage, and compressing a pair of springy lungs. This pushes air up through the smaller airways, collapsing rings of cartilage as oxygen travels out from the lungs, to be held in the larger, upper airways. Upon surfacing, this air will be used to re-inflate the lungs, but for now their heart slows down to preserve oxygen. Blood flow is redirected towards only the most essential organs like the heart, lungs, and brain, which rely on reserve oxygen stored in blood and muscle. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
为找到最喜欢的食物，海狮的水下捕食深度远超许多半水栖同类。有些海狮种类可下潜到近400米，面对不断增加的水下压力，它们收缩柔韧的肋骨、压缩富有弹性的肺。使肺部空气上行通过狭窄呼吸道，肺部氧气流出时，软骨环同时收缩，把空气封闭在更大的上呼吸道中。浮出水面时，这些空气又会重新充满肺部，但现在，它们要减缓心跳来节省氧气。血液流向被改变，仅流经最重要的器官，如心脏，肺和大脑，这些器官依赖于血液和肌肉中储备的氧气。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
Once they arrive at their hunting ground, sea lions depend on their superior vision to find their prey. Most mammal eyes have a structure called a lens– a transparent, convex structure whose shape refracts light to enable sight. In humans, this lens is curved to process light waves traveling through air. But sea lions need to see their best at hundreds of meters deep. To accommodate, their eyes have a much rounder lens to refract light underwater, as well as teardrop-shaped pupils which can expand to 25 times their original size. This lets in as much light as possible, helping them pinpoint their prey in even the dimmest conditions. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
一旦抵达猎场，海狮凭借绝佳视力来发现猎物。多数哺乳动物的眼睛都有一种晶状体结构——一种透明、凸起的结构，可折射光线成像。人类的晶状体是弧形的，可以处理穿过空气的光波，但海狮需要看清几百米深的地方。为了适应环境，它们拥有更圆的晶状体来折射水下光线，同时还拥有泪珠状的瞳孔，其瞳孔可以扩大25倍。这可以使尽可能多的光线进入眼睛，帮它们在最昏暗的环境下准确地找到猎物。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
But once they’ve closed in, they rely on something akin to a sixth sense to actually catch their meal. Their whiskers, or vibrissae, are composed of keratin and full of nerve fibers that run deep into the connective tissue of their face. Sea lions have full directional control over these whiskers, which can lie flat against their face, or stick out at a 90-degree angle. When properly tuned, these whiskers can sense the slim trails of moving water fish leave in their wake. And they’re precise enough to let blindfolded sea lions tell the difference between objects less than two centimeters different in size. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
但一旦它们接近了猎物，它们依靠类似第六感来捕获食物。它们的胡须，或触须，由角蛋白组成，富含神经纤维，神经纤维深入其脸部结缔组织。海狮可全方位控制胡须，既可平贴脸上，也能90度直直探出。适当调整后，胡须能感知鱼儿游动留下的细小痕迹。蒙眼的海狮可以通过胡须精确地区分大小相差不到两厘米的物体。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
With these tools a healthy sea lion can catch generous helpings of fish such as anchovy, mackerel, and squid on every outing. And with their exceptional memories, they can remember multiple hunting grounds, including those they haven’t visited in decades. This memory also extends to breeding territories and birthing areas, as well as which neighbors are friend and foe. There’s even evidence that sea lions can remember how to perform tasks after 10 years with no practice in between, letting them navigate old stomping grounds with ease. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
借助这些工具，健康的海狮每次外出时都能捕获大量鱼类，如凤尾鱼，鲭鱼和鱿鱼。凭借超凡记忆力，它们能记住多个猎场，包括几十年没去的猎场。海狮也能记住繁殖和分娩区域，以及那些邻居是敌是友。甚至有证据表明，海狮还能记住如何在某地狩猎，即使10年没在那里狩猎，这种超强记忆令其轻松巡游旧地盘。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
Yet despite these incredible adaptations, there are changes unfolding in their habitats too rapidly for sea lions to handle. As climate change warms the oceans, certain toxic algae species thrive. This algae is harmless to the fish who eat it, but for the sea lions which ingest those fish, the algae’s domoic acid can trigger seizures and brain damage. Changing ocean conditions keep this algae blooming year round, causing more and more sea lions to wash up on beaches. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
然而，尽管有这些惊人的适应力，栖息地的变化还是快得让海狮难以适应。随着气候变化让海洋变暖，某些有毒藻类繁荣生长。这种藻类对吃它的鱼无害，但对于以这些鱼为食的海狮来说，藻类的软骨藻酸会引发癫痫和脑损伤。不断变化的海洋环境使这种藻类终年繁盛，导致越来越多的海狮死亡，被冲到海滩上。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
This tragic discovery is just one of the many ways the health of aquatic animal communities can help us better understand Earth’s oceans. These red flags help us take action to protect ourselves and other maritime mammals. And the more we can learn about the changing ocean that sea lions inhabit, the better equipped we’ll be to help these clever creatures thrive. 文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
这种悲剧的发现只是，我们通过水生动物健康状况，来更好地了解地球海洋的方式之一。这些红色警示帮助我们采取行动，去保护自己和其它海洋哺乳动物。越了解海狮栖息地海洋的变化，我们就能更好地帮助这些聪明的动物繁衍壮大。文章源自：力哥爱英语（ienglish521.com）力哥爱英语-https://ienglish521.com/2682.html
