VOA新闻杂志2023--Race to Help Largest, Rarest Tortoise

Race to Help Largest, Rarest Tortoise

The average life expectancy¹ of North America's largest and rarest tortoise species is unknown. But scientists say the animals could live more than 100 years.

The Bolson tortoise is an endangered species. Saving it from extinction² is a long-term project. But a conservation effort took a step toward that goal last week.

United States wildlife officials reached an agreement with the Turner Endangered Species Fund. The deal permits the release of Bolson tortoises on land owned by Ted³ Turner, a media industry leader.

The release of captive tortoises on the Armendaris Ranch⁴ is designed to create a free-roaming population. Last week, 20 adult tortoises were released on the property, which is already home to 23 of them. There are also many younger tortoises.

The tortoises usually spend about 85 percent of the time in their underground burrows⁶, which in some cases can be about 20 meters long. The animals live long lives and are slow to reproduce.

Shawn Sartorius is with the Fish and Wildlife Service. He said the results of the breeding and restoration project will not be seen in his lifetime.

"What we're doing here is establishing a population here that can be handed off to the next generation," Sartorius said.

It is a step toward one day releasing the tortoises in more places in the Southwest. Conservationists are also pushing the federal government to consider creating a recovery plan for the species. The tortoise is part of a growing effort to find new homes for endangered species as they flee climate change and other threats to their natural habitats.

Wild Bolson tortoises are found only in the grasslands⁷ of north-central Mexico. The animal once lived in a much greater area that included the southwestern United States. Fossil records also show it was once present it the southern Great Plains, including parts of Texas and Oklahoma.

Scientists estimate the wild population of Bolson tortoises in Mexico is under 2,500. Experts say the animals are hunted as food and as pets. Their habitat is shrinking, as more desert grasslands become farmland.

The 1,450 square kilometer Armendaris Ranch appears to be a great area for the tortoises. In all, the Turner Endangered Species Fund and its partners have been able to grow the population from 30 tortoises to about 800, said Chris Wiese. She leads the project at the Armendaris Ranch.

"The releases are the essential step to getting them back on the ground and letting them be wild tortoises," she said.

The tortoises released last week will be able to live freely in the 6.6-hectare pen. They are given electronic trackers, and wildlife workers will check on them once a year.

Depending on weather and other factors, it can take a few years or more for a hatchling to reach just over 110 millimeters long. They can eventually grow to about 370 millimeters.

The species was unknown to science until the late 1950s and has not been studied closely.

The goal is to build a strong captive population that can be used as research for future releases into the wild — both in the U.S. and Mexico. That work will include getting state and federal permits to release tortoises outside Turner lands.

Those recently released hit the ground crawling. They wandered through grass and around desert plants as the Fra Cristobal mountain range appeared in the distance.

It was a moment that Wiese and her team have been working toward for years.

"We are not in the business of making pets," she said. "We're in the business of making wild animals and that means you have to let them go."

Words in This Story

species — n. a group of animals or plants that are similar and can produce young animals or plants

extinction — n. the state or situation that results when something has died out completely

ranch — n. a large farm especially in the U.S. where animals are raised

burrow⁵ — n. a hole or tunnel in the ground that an animal makes to live in or for safety

breed — v. to keep and take care of animals or plants in order to produce more animals or plants of a particular kind

fossil — n. something that is from a plant or animal which lived in ancient times and that you can see in some rocks

essential — adj. extremely important and necessary

 

pen — n. a small enclosed area for farm animals

1 expectancy   

n.期望，预期，（根据概率统计求得）预期数额

参考例句：

• Japanese people have a very high life expectancy.日本人的平均寿命非常长。
• The atomosphere of tense expectancy sobered everyone.这种期望的紧张气氛使每个人变得严肃起来。

2 extinction   

n.熄灭，消亡，消灭，灭绝，绝种

参考例句：

• The plant is now in danger of extinction.这种植物现在有绝种的危险。
• The island's way of life is doomed to extinction.这个岛上的生活方式注定要消失。

3 ted   

vt.翻晒，撒，撒开

参考例句：

• The invaders gut ted the village.侵略者把村中财物洗劫一空。
• She often teds the corn when it's sunny.天好的时候她就翻晒玉米。

4 ranch   

n.大牧场，大农场

参考例句：

• He went to work on a ranch.他去一个大农场干活。
• The ranch is in the middle of a large plateau.该牧场位于一个辽阔高原的中部。

5 burrow   

vt.挖掘(洞穴)；钻进；vi.挖洞；翻寻；n.地洞

参考例句：

• Earthworms burrow deep into the subsoil.蚯蚓深深地钻进底土。
• The dog had chased a rabbit into its burrow.狗把兔子追进了洞穴。

6 burrows   

n.地洞( burrow的名词复数 )v.挖掘（洞穴），挖洞( burrow的第三人称单数 )；翻寻

参考例句：

• The intertidal beach unit contains some organism burrows. 潮间海滩单元含有一些生物潜穴。 来自辞典例句
• A mole burrows its way through the ground. 鼹鼠会在地下钻洞前进。 来自辞典例句

7 grasslands   

n.草原，牧场( grassland的名词复数 )

参考例句：

• Songs were heard ringing loud and clear over the grasslands. 草原上扬起清亮激越的歌声。 来自《现代汉英综合大词典》
• Grasslands have been broken and planted to wheat. 草原已经开垦出来，种上了小麦。 来自《简明英汉词典》