when people think of Florida, they usually think of alligators
提到佛罗里达，人们通常会想到短吻鳄
hundreds of species of large marine animals live in the waters of Florida like the alligators
数百种大型海洋动物生活在佛罗里达水域，比如短吻鳄
the alligators big and mean, but today we're going to meet an animal that's big and gentle
短吻鳄体型较大而且不好亲近，但今天我们要去见一种大只但很温驯的海洋动物
I'm talking about the Florida manatee, manatees are marine mammals
我说的是佛罗里达海牛，海牛是海洋哺乳动物
and they're huge which is no surprise since their distant relatives of the elephant
它们体型巨大，这并不奇怪，因为它们是大象的远亲
but manatees are among the most gentle animals on earth
海牛是地球上最温驯的动物之一
hi I'm Jonathan bird and welcome to my world
大家好，我是乔纳森·伯德，欢迎来到我的世界
it's hard to understand what's so amazing about manatees until you've been in the water with one and looked at right in the eye
当下水并和海牛双眼对视时，你才会明白海牛的神奇之处
today I'm going swimming with manatees in the backyard of the Cisco family in Crystal River Florida
今天，我要去佛罗里达水晶河Cisco家族的后院和海牛一起游泳
the sisto's live on a canal where manatees hang out during the winter
Cisco一家人居住在运河边上，冬天海牛们会在那里逗留
manatees don't like the oceans chilly winter temperatures, the canal fed by a warm water spring is just right
海牛不喜欢冬季海洋寒冷的温度，温泉供给的河水温度恰到好处
the canal falls within the Crystal River National Wildlife Refuge in Florida which protects manatees
这条运河坐落于佛罗里达州的水晶河国家野生动物保护区，海牛在那里得到保护
the sanctuary sets limits on human manatee contact
保护区限制与海牛接触
people can swim with manatees if they respect the animals
如果人们尊重海牛，可以和海牛一起游泳
they must also stay out of the special roped off areas set aside for those manatees that don't want to be bothered
他们还必须远离特殊区域，该区域专为不想被打扰的海牛而划定
the manatees that like the attention let people get pretty close
喜欢受到关注的海牛允许人们靠近
I finally look one in the eye
我终于和它们对视了
what I see is unbelievable, with the help of a special piece of diving gear called a rebreather
眼前的一切简直难以置信，在一种叫做换气器的特殊潜水装备的帮助下
I'm able to watch a manatee sleep
我能看到海牛在睡觉

because the rebreather produces fewer bubbles and noise than ordinary scuba gear
因为换气器比普通水肺装置产生的气泡和噪音更少
my approach doesn't startle the animal and wake it up
这种方式并没有吓到也没有唤醒海牛
the manatee doesn't even know I'm here
海牛甚至不知道我在这儿
I think it might be snoring, look at that thing it's completely zonked out
我想可能是海牛打呼噜了，看那个，它完全被弄晕了
manatees can stay underwater for as long as 20 minutes
海牛可以在水下停留长达20分钟
so even during sleep they must periodically rise to the surface to breathe
因此，即使在睡眠期间，它们也必须定期浮到水面上来呼吸
they gently float up to take a breath
它们轻轻地浮起来呼吸
and then gently sink back down like they're in a dream the whole time
然后轻轻地沉下去，就像一直在梦中一样
the rebreather also helps me get close to a mother and her calf without startling them
换气器还可以助我接近牛妈妈和小牛，而不会吓到它们
notice the calf nursing from the back of her mother's flipper
我注意到小牛在牛妈妈的背鳍里哺乳
it's one reason scientists think that manatees and elephants probably evolved from the same ancestor
这也是科学家认为海牛和大象可能是由同一祖先进化而来的原因之一
elephants nurse in the region of the mother's armpit to
大象在妈妈的腋窝处哺乳
the mother and calf seemed to communicate in part through a series of sounds or vocalizations
某种程度上，母牛和小牛似乎通过一系列声音或鸣叫进行交流
calves stay with their mother for one to two years before going off on their own
小牛会和它们的妈妈呆上一两年，然后自己出发
fully grown this calf could be 15 feet long and weigh 3,000 pounds
这只成年的小牛身长可达15英尺，重达3000磅
but manatees can't cope very well with all the new people who come to live in Florida every year
但是海牛无法与每年前来佛罗里达州定居的所有人处理好关系
why, well for one thing, their food supply is disappearing
为什么，一方面，海牛的食物供给正在消失
over a thousand people move to Florida every day, and they all want to live near the water
每天有超过一千人搬到佛罗里达州，他们都想靠水而居
so they build houses near the water and they have to build these sea walls to keep the houses from falling in
所以这些人在水边建房筑堤以防止房子坍塌
the problem is that the plants manatees eat can't grow on sea walls
问题是海牛食用的植物无法在海堤上生长
manatees are sometimes called sea cows and that's because they only eat plants
海牛有时被称为海中的牛，这是因为它们只吃植物
in fact is the only marine mammal that each just plants
事实上，它是唯一以植物为食的海洋哺乳动物
manatees spend eight hours a day feeding and may consume 200 pounds of vegetation
海牛每天要花8小时进食，可能要消耗200磅的植物
as vegetarians manatees farm no other animals and pose no danger to man
由于海牛是素食主义者，所以它们不吃其它动物，也不会对人类构成威胁
but here's the problem, sea walls designed to keep houses from falling into the water can't grow the shallow plants that manatees eat
但问题是，为了防止房屋落水而设计的海堤无法种植海牛赖以为生的浅水植物
the manatees food supply and its habitat are disappearing
海牛的食物供应和栖息地正在消失
and here's another problem speedboats
这是另一个问题，快艇
manatees are slow and boats hit them
海牛行动缓慢，被船只撞上了