VOA标准英语2010年-New Life for Vanishing Species

New technologies aid in conservation efforts at the National Zoo

Susan Logue Koster | Front Royal, Virginia 19 July 2010

 The National Zoo opened a cheetah¹ science facility in 2007 at its conservation center in Front Royal, VA. Cheetahs² are considered vulnerable.

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For more than a century, the National Zoo in Washington has attracted visitors wanting to learn more about animals.  Some 2,000 animals are currently in the collection, ranging from ants to elephants.

For half its history, exhibiting animals was its primary role, but the National Zoo has become a leader in wildlife conservation.

Resurrecting vanishing species

Visitors to the National Zoo can see animals representing nearly 400 species. About one fifth of them are considered threatened or endangered, like the Andean bear.

The media turned out in May for the formal introduction of two young cubs³ born this winter. They were the first to be born at the zoo in 22 years and the first to survive in North America since 2005.

"So we truly have a success story here, both for us and for conservation of species in its range country," says Dennis Kelly, director of the Smithsonian National Zoo.

Red pandas have been another success. There are fewer than 2,500 left in the wild, due to habitat loss in China, the Himalayas and Myanmar. The National Zoo has been responsible for the birth of more than 120 cubs.

Nurturing⁴ wildlife in the mountains of Virginia

Most were born about 100 kilometers from the zoo, at a 1,700-hectare campus nestled in the Shenandoah Mountains of Virginia, headquarters of the Smithsonian Conservation Biology Institute (SCBI).

"There are 225 zoos in the United States and only about five zoos have large off-site facilities like this one," says Steven Monfort, director of the SCBI. "What we try to do is have high profile species that are in need of science or breeding attention." 

Between 30 and 40 species of mammals and birds are at the campus. Species like the Przewalski's horse, which originated on the steppes of Western Europe and Asia.

"We have 27 individuals here, the largest managed population in the United States," Monfort says. "That species was down to 12 purebred individuals after World War II. Now there are more than 1,500 in the world."

More than 400 have been reintroduced to China, Mongolia and Kazakhstan. Such successes lead to high expectations.

Monfort says zoos are too often asked to make miracles happen when a species is down to an incredibly small number of individual animals.

 VOA - S. Logue Koster
These Andean bear cubs, born in January 2010, were the first to be born at the National Zoo in 22 years.

That was the case with the black-footed ferret, which is native to the American prairie. Twenty years ago, there were only 18 in the wild.  "They were thought to be extinct and a small population was found," Monfort says.  

Since then, more than 500 black-footed ferrets have been born at the National Zoo, many using artificial insemination and frozen sperm⁵.  Through reintroduction into the wild, the population has grown to 700.

Scientific advances aid progress

Advances in science have helped conservation in other ways.  Scientists can now monitor hormones⁶ using fecal or urine samples. That helped researchers learn that when two female cheetahs are together, one can reproductively suppress the other.

DNA⁷ research also plays a role.

"They do population management designs for endangered and threatened species," says Rob Fleischer, head of the Center for Conservation and Evolutionary⁸ Genetics in the SCBI.  "If the animals are in captivity¹⁰, we try to mix them up more, try to make sure to design the breeding program so we don't lose genetic⁹ variability."

 
VOA - S. Logue Koster
Rob Fleischer (right), head of the Center for Conservation and Evolutionary genetics, says scientists at the Zoo's new DNA lab work on nearly all of the Zoo's conservation efforts

Although scientists at the zoo work with ancient DNA from animals that have been dead thousands of years or more, they won't be resurrecting any extinct animals any time soon, Monfort says. 

"One of the things that bothers me the most about these high technology ideas of bringing back species from the dead is that the problems that we are facing today are so dramatic and species are declining so quickly that it is triage at best."

As it works to preserve vulnerable animals, the Smithsonian Conservation Biology Institute is also training the next generation of biologists to carry on their work. It has already trained over 4,000 professionals, as well as hundreds of graduate and post doctoral fellows from every continent.

"We need an army of people.," Monfort says, " The problems we are talking about aren't going to be solved in a single person's career."  He says the challenges to wildlife - climate change, invasive species, and other human impacts on the environment - will continue. 

 

1 cheetah   

n.(动物)猎豹

参考例句：

• The cheetah is generally credited as the world's fastest animal.猎豹被公认是世界上跑得最快的动物。
• The distribution of the cheetah ranges from Africa to Central Asia.印度豹的足迹遍及从非洲到中亚的广大地区。

2 cheetahs   

n.（奔跑极快的）非洲猎豹( cheetah的名词复数 )

参考例句：

• Unlike lions or cheetahs, leopards are secretive, solitary cats. 花豹不像狮子或印度豹，是属于较神秘而隐居的大猫。 来自互联网
• Among this lot are cheetahs, lions, leopards, rhinoceroses, spotted hyenas and elephants. 印度豹、狮子、花豹、犀牛、斑点土狼、大象等，都是此地的居民。 来自互联网

3 cubs   

n.幼小的兽，不懂规矩的年轻人( cub的名词复数 )

参考例句：

• a lioness guarding her cubs 守护幼崽的母狮
• Lion cubs depend on their mother to feed them. 狮子的幼仔依靠母狮喂养。 来自《简明英汉词典》

4 nurturing   

养育( nurture的现在分词 )； 培育； 滋长； 助长

参考例句：

• These delicate plants need careful nurturing. 这些幼嫩的植物需要精心培育。
• The modern conservatory is not an environment for nurturing plants. 这个现代化温室的环境不适合培育植物。

5 sperm   

n.精子，精液

参考例句：

• Only one sperm fertilises an egg.只有一个精子使卵子受精。
• In human reproduction,one female egg is usually fertilized by one sperm.在人体生殖过程中，一个精子使一个卵子受精。

6 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

7 DNA   

(缩)deoxyribonucleic acid 脱氧核糖核酸

参考例句：

• DNA is stored in the nucleus of a cell.脱氧核糖核酸储存于细胞的细胞核里。
• Gene mutations are alterations in the DNA code.基因突变是指DNA密码的改变。

8 evolutionary   

adj.进化的；演化的，演变的；[生]进化论的

参考例句：

• Life has its own evolutionary process.生命有其自身的进化过程。
• These are fascinating questions to be resolved by the evolutionary studies of plants.这些十分吸引人的问题将在研究植物进化过程中得以解决。

9 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

10 captivity   

n.囚禁；被俘；束缚

参考例句：

• A zoo is a place where live animals are kept in captivity for the public to see.动物园是圈养动物以供公众观看的场所。
• He was held in captivity for three years.他被囚禁叁年。