In the American state of Florida , rancher Jim Strickland can see his cows at any time , day or night .
在美國佛羅里達州，牧場主吉姆·史崔克蘭無論白天黑夜，隨時都能看到他的牛。
To do this , all he needs is his phone .
要做到這一點，他只需要一支手機。
Strickland uses virtual fencing to watch and control the movements of his animals .
史崔克蘭利用虛擬圍欄來觀察和控制牲畜的活動。
It can also help improve animal health .
它還有助於改善牲畜的健康。
Strickland has been using the system for about six months .
史崔克蘭使用這套系統已經大約六個月了。
“It has exceeded by far my expectations .”
「它遠遠超出了我的預期。」
Virtual fencing uses radio signals to make an invisible fence .
虛擬圍欄利用無線電訊號形成一道看不見的圍欄。
This means you cannot see the fence .
也就是說，你看不見這道圍欄。
This keeps animals within , or outside of , certain areas .
這樣就能把牲畜留在某些區域之內，或擋在其外。
The signals come from nearby mobile phone towers .
訊號來自附近的手機基地台。
The signals can also come from base stations that can be moved using a small truck .
訊號也可以來自用小卡車就能移動的基地台。
Each animal wears a collar around its neck .
每頭牲畜的脖子上都戴著一個項圈。
The collar has a radio signal receiver and a GPS device that shows the animal's location .
項圈上有一個無線電訊號接收器和一個顯示牲畜位置的GPS裝置。
Ranchers train livestock to connect a sound with a small electric shock .
牧場主訓練牲畜把一種聲音和輕微的電擊聯想在一起。
When an animal gets close to a virtual fence , its collar makes a warning sound .
當牲畜靠近虛擬圍欄時，項圈會發出警告聲。
If the animal moves even closer to the fence , it receives a shock .
如果牲畜繼續靠近圍欄，就會受到電擊。
In this way , livestock quickly learn to stay away from the fence .
這樣，牲畜很快就學會遠離圍欄。
Ranchers can change the virtual fence boundaries quickly by using a phone App or computer .
牧場主可以用手機應用程式或電腦迅速更改虛擬圍欄的邊界。
And livestock quickly learn the new boundaries .
牲畜也會很快熟悉新的邊界。
Strickland and his coworkers can use their phones even while on horseback to move cattle from one area to another .
史崔克蘭和同事們甚至可以在騎馬時用手機把牛從一個區域趕到另一個區域。
All they need to do is change the virtual fence lines .
他們只需要更改虛擬圍欄的界線就行了。
“And every 30 minutes , that line will move down ; it will literally drive those cows down .”
「每隔30分鐘，那條線就會往下移，真的就把那些牛往下趕。」
Physical fences take time , labor and money to build .
興建實體圍欄需要時間、人力和金錢。
It can be difficult to put them in areas such as rocky and hilly land , wet areas , or places with thick vegetation .
在多岩石的丘陵地帶、潮濕地區或植被茂密的地方，很難興建圍欄。
Over time , fences need to be fixed or new ones need to be built .
時間一長，圍欄就需要修補或重建。
When hurricane Ian hit Florida last year , it destroyed four houses and 45 kilometers of physical fence on the land where Strickland works .
去年颶風伊恩襲擊佛羅里達時，摧毀了史崔克蘭工作的那片土地上的四棟房屋和45公里實體圍欄。
But the cell towers for the virtual fence system kept working .
但虛擬圍欄系統的基地台仍在正常運作。
Physical fences can also harm wild animals by making it difficult for them to move within and to areas they need for survival .
實體圍欄還可能傷害野生動物，讓牠們難以在生存所需的區域內活動或前往這些區域。
The Nature Conservancy (TNC ) is a U.S-based environmental non-profit organization .
大自然保護協會（TNC）是一家總部設在美國的非營利環保組織。
It has partnered with cattle ranches in the states of Kansas , New Mexico and Colorado to research the effects of virtual fencing .
該組織與堪薩斯州、新墨西哥州和科羅拉多州的養牛場合作，研究虛擬圍欄的效果。
William Burnidge is Deputy Director of TNC's North America Regenerative Grazing Lands Strategy .
威廉·伯尼奇是大自然保護協會北美再生放牧地策略的副主任。
He said that by changing fence boundaries , the systems prevent animals from eating too much vegetation within one area .
他說，透過改變圍欄邊界，這套系統可以防止牲畜在同一區域吃掉過多植被。
This helps plants regenerate , or grow again .
這有助於植物再生，也就是重新生長。
He added that virtual fences could help protect rare plants and areas near rivers and streams .
他補充說，虛擬圍欄可以幫助保護珍稀植物以及河流和溪流附近的區域。
They could also support conservation of wild animals , improve the health of animals and help ranch workers have a better quality of life .
它們還能支持野生動物保育，改善牲畜健康，並幫助牧場工人提高生活品質。
Strickland works with partners at Florida Conservation Group and the University of Florida .
史崔克蘭與佛羅里達保育組織和佛羅里達大學的夥伴們合作。
With virtual fences , they can carefully control grazing .
有了虛擬圍欄，他們可以精細地控制放牧。
This helps them research the effects of grazing patterns on the growth of young cows , birth rates , and even the effects on nesting birds .
這有助於他們研究放牧模式對小牛生長、出生率，甚至對築巢鳥類的影響。
They also plan to research how grazing can affect the release of carbon dioxide gas into the atmosphere .
他們還計畫研究放牧會如何影響二氧化碳向大氣中的排放。
In Florida and other places , fields are sometimes burned to prepare them for future grazing .
在佛羅里達和其他地方，人們有時會焚燒草場，為日後的放牧做準備。
The burning releases carbon .
焚燒會釋放碳。
Virtual fences may help reduce burning by better controlling where and how long cattle graze .
虛擬圍欄可以更好地控制牛在哪裡吃草、吃多久，從而有助於減少焚燒。
Both Strickland and Burnidge note that , unlike physical fences , livestock cannot not get injured by a virtual fence .
史崔克蘭和伯尼奇都指出，與實體圍欄不同，牲畜不會因虛擬圍欄而受傷。
The GPS collars also let ranchers watch for animals that may be having problems .
GPS項圈還能讓牧場主留意可能出了問題的牲畜。
For example , if the system shows that a cow has not moved for many hours , it may be sick or injured .
例如，如果系統顯示一頭牛好幾個小時都沒動過，牠可能生病或受傷了。
Cattle can easily damage burned areas and the young plants that grow there .
牛很容易破壞焚燒過的區域以及那裡新長出的幼苗。
The Oregon study showed that cows without virtual fence collars ate nearly 70 percent of the plants available to them in a burned area .
奧勒岡州的研究顯示，沒戴虛擬圍欄項圈的牛吃掉了焚燒區內近百分之七十的可食植物。
However , cows with collars spent very little time in the burned area and ate less than three percent of the plants available to them .
然而，戴著項圈的牛在焚燒區內停留的時間很短，吃掉的植物不到百分之三。
Although virtual fencing systems have benefits , they can be costly .
雖然虛擬圍欄系統有很多好處，但成本可能很高。
A collar for just one animal can cost around $50 each year or more .
僅一頭牲畜的項圈每年就可能要花約50美元甚至更多。
And portable base stations cost $10,000 or more .
而可攜式基地台要1萬美元或更多。
Researchers are looking for ways to lower costs and bring the technology to developing countries .
研究人員正在尋找降低成本的方法，把這項技術帶到開發中國家。
Last year , the Bezos Earth Fund awarded $9.9 million to Cornell University's College of Agriculture and Life Sciences to develop low-cost virtual fencing .
去年，貝佐斯地球基金向康乃爾大學農業與生命科學學院撥款990萬美元，用於開發低成本虛擬圍欄。
The university plans to test new systems in Kenya , Mongolia , Argentina , Brazil and Colombia .
該校計畫在肯亞、蒙古、阿根廷、巴西和哥倫比亞測試新系統。
But in some areas , virtual fencing may not be the best solution , Burnidge said .
但伯尼奇說，在某些地區，虛擬圍欄可能不是最佳解決方案。
When Burnidge visited Kenya , he saw many workers who closely follow and take care of livestock .
伯尼奇造訪肯亞時，看到許多工人緊跟在牲畜身邊照料牠們。
Virtual fences could cause some of these workers to lose their jobs .
虛擬圍欄可能會導致其中一些工人失業。
Still , Burnidge said , many people want to learn more about the technology .
儘管如此，伯尼奇說，很多人都想進一步了解這項技術。
And Strickland said they are already working on more ways virtual fencing can be used .
史崔克蘭說，他們已經在研究虛擬圍欄的更多用途。
“Now we're seeing so many things .
「現在我們看到了很多東西。
Once you start down the road of new technology , then it starts expanding . . .
一旦你走上了新技術這條路，它就會不斷擴展……
It's like , what can we do next ?” he said .
就像是，我們接下來還能做什麼呢？」他說。