Bat plague: The mystery disease that threatens to wipe species out and why we depend on their survival
Last updated at 7:56 AM on 24th May 2010
They may not be cute or cuddly and they suffer from a decidedly bad Press, but we will certainly miss them if they go.
他們可能不是很可愛或逗人喜愛，和牠們遭受一明確地壞的消息，但我們一定會懷念牠們如果牠們失去。
Bats are the hidden guardians of Britain's ecosystems and scientists fear they might be in peril.
蝙蝠是英國生態系統的隱藏監護人和科學家擔心牠們可能會處於危險中。
Our landscapes, crops, biodiversity and even potential for medical research into human diseases could be changed for ever.
我們的景觀，農作物，生物多樣性和甚至是潛質為人類疾病的醫學研究，將可能會永遠改變。
A mystery disease is sweeping across North America, starving bats to death and leaving behind mass graves of thin, putrefied and fungus-ridden bodies.
一種神秘的疾病正橫掃北美，將蝙蝠飢餓至死亡和留下薄、腐爛和黴菌困擾的屍體的萬人塚。
In Peril: U.S. Townsend's Big-Eared Bat are succumbing to a mystery disease危險中：美國湯森的大耳蝙蝠在屈從於一種神秘疾病
The mysterious killer has been dubbed White Nose Syndrome (WNS) in America, where it was first discovered in a cave in New York State four years ago.
神秘的殺手在美國被稱為白鼻綜合症（WNS），4年前它第一次在紐約州被發現在一個山洞裡。
It attacks its victims during their winter hibernation and leaves them with a powdery white fungus on their noses, muzzles and wings.
它襲擊它的受害者在牠們的冬季休眠期，和在牠們的鼻子、鼻口部分和翅膀上留給牠們一白色粉末的真菌。
It is believed that the fungus is an irritant, waking up the bats repeatedly and causing them to exhaust the body-fat reserves needed to get them through hibernation.
據相信真菌是一種刺激劑，一再喚醒蝙蝠和導致牠們用盡身體脂肪，儲備需要用於讓牠們經過休眠狀態。
Once WNS hits a cave, its entire bat population - sometimes tens of thousands of bats - can die.
一旦WNS打擊一個山洞，牠的整個蝙蝠人口 - 有時數以萬計的蝙蝠 - 可能死去。
In Britain, our most common bat, the pipistrelle, can live in colonies of up to 1,000 but in North America and, occasionally, continental Europe, tens of thousands of bats can live in one 'hibernaculum'.
The biggest known bat colony houses 24million bats in Bracken Cave, Texas.
About one million bats have died since the North American epidemic started. Reports of the fungus (Geomyces destructans), thought to be cause of the disease, have surfaced in a handful of bats across Europe, although none has died. Bats with white fungal growth on their noses have also been reported in Britain, although so far none has tested positive for Geomyces.
Professor Paul Racey at the University of Exeter, who is an adviser to the UK's Bat Conservation Trust says: 'Although Geomyces destructans has been found in Europe, at this point we don't have mass mortality.
'We just have the fungus and we hope it stays that way.'
However, he and other bat experts fear the situation in America could be replicated in Europe - and yet the issue has had nowhere near the amount of coverage devoted to the 'colony collapse disorder' that has been killing off bees. Unfortunately for bats, we just don't like them.
Despite the fact that they are vilified in the vampire tales of yore, and blamed as carriers of deadly diseases such as rabies and Ebola, we need bats for lots of reasons.
First, with 18 species in this country, bats are a part of the fabric of our natural heritage.
winging it: The Pipistrelle bat, more common in Britain, could also killed by the plague if it crosses the Atlantic搧翼：伏翼蝙蝠更常見於英國，亦可能被瘟疫殺害，如果它穿越大西洋
There are also serious practical and economic implications. 'Colonies of bats eat an enormous number of insects each night,' says Prof Racey. 'A bat can feed on ten insects a minute. If it feeds for maybe three hours a night, clock that up over a summer, you start getting into tons.'
Because some of those insects are crop pests, bats save farmers a fortune on pesticides. In America, experts estimate that pests uneaten by WNS-affected bats cost farmers billions of dollars each year. And, of course, the less pesticide farmers use, the healthier the environment.
And there are knock-on effects associated with bat deaths.
Dr Emma Teeling, a bat expert at University College Dublin, says: 'Ecosystems all depend on the interactions of all the creatures in them.
Remove one - and you don't know the consequences.' For example, with bats removed from the equation, we could suddenly see droves of midges. It's possible that populations of less desirable bugs could out-compete the 'good guys' - the insects that help us by pollinating crops.
Bats may even be keeping nasty disease-carrying bugs from gaining a foothold in Britain. Bats eat a midge called Culicoides, which carries bluetongue, a devastating livestock disease that is moving northwards in Europe as a result of climate change.
The extreme nature of bats also makes them valuable in helping to understand human health. With a life-span of up to 30 years, they live disproportionately long lives compared with other mammals. A mouse for example, lives for about a year.
Studying bat metabolism could help us understand human metabolic disorders, says Dr Teeling. Likewise, comparing bat genes to human genes could give us clues to blindness and deafness.
Outside Europe, bats are important pollinators of night-blooming flowers, and as seed dispersers. They pollinate the agave cactus from which tequila is made, and fruits such as bananas, mangoes and guavas depend on them.
And bats have been real survivors, constituting an astonishing 20 per cent of all living mammal species today. Even their reputation as the bad guys of gothic horror are unjustified. Of the 1,100 or so bat species, only three feed on blood.
Experts don't yet know if British bats face the carnage suffered by their American cousins, but they are concerned - enough to start raising awareness in Europe and lobbying governments to take the threat of WNS seriously.
'The search continues for Geomyces in Europe. The number of dots on the map are increasing,' says Prof Racey. 'European scientists have been collecting and testing samples for the WNS fungus from bats across Europe since last spring. Five countries have tested positive: France, Hungary, Germany, Switzerland and the Czech Republic.'
Though scientists still can't say that the fungus is the definitive cause of WNS, it is looking increasingly likely.
But why is it not yet killing European bats? One theory is that our bats are immune to WNS, perhaps having had it long ago. It could have been transported to America from Europe, possibly via a tourist or caver, and since the bats there hadn't encountered it before, they were especially vulnerable.
Another theory is that the fungus may have mutated slightly in North America, turning it into a killer. This is what happens with human diseases such as flu - a small genetic change can make something mild turn virulent. If this is the case, then our bats may be in real trouble.
Sixty experts from 30 European countries, along with a handful of American scientists, have laid out a battle plan for Europe. The group will submit its plan to a leading ecology and conservation journal within the next few weeks. Governments are to be asked to raise awareness of WNS, particularly among cavers and tourist-cave operators.
In America, government-owned caves are being closed in an attempt to curb the spread of WNS, and privately owned caves have been encouraged to shut. Prof Racey hopes that in Europe, cave owners will ask visitors if they have recently visited caves in North America and, if the answer is yes, prevent entry.
Meanwhile, the killer is still rampaging across America. Last week it had spread from its epicentre in New England to 13 states and it has also recently entered Canada.
Peter Youngbaer, the liaison on WNS for America's caving organisation, the National Speleological Society, says: 'Our major worry is that there is no apparent progress on any solution.'
Scientists are working hard to find the disease's weak spots, but WNS remains elusive. The genome of the suspect American fungus is currently being sequenced at the Broad Institute in Cambridge, Massachusetts. It is hoped that this will provide a blueprint to compare to the genome of the European strain, and help work out why the American version appears so deadly.
The hunt for a cure is also on. American researchers are currently testing fungicides - including one similar to that used to treat athlete's foot - on the WNS fungus and bats.
Europe can't afford to be complacent. Bats have emerged from hibernation now, but they could be vulnerable to WNS as they enter hibernation again later this year.
Dr Teeling warns: 'We have another winter coming up. We can't just sit here and wait.'
http://www.dailymail.co.uk/sciencetech/article-1280531/Bat-plague-The-mystery-disease-threatens-wipe-depend-survival.html
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