|
White-nose syndrome (WNS) is an emerging disease in North American bats which as of 2012 was associated with at least 5.7 million bat deaths. The condition is named for a distinctive fungal growth around the muzzles and on the wings of hibernating bats and was first identified from a February 2006 photo taken in a cave in Schoharie County, New York. It has rapidly spread. As of September 2014, the fungus has been found in caves and mines of 25 states throughout the Northeastern U.S., as far south as Mississippi, as far west as Missouri and as far north as five Canadian provinces.〔(【引用サイトリンク】title=Three cases of bat disease discovered in Missouri )〕〔(【引用サイトリンク】title=Bat White Nose Syndrome (WNS) by Occurrence by County/District NSS WNS Map )〕 The disease is caused by the fungus ''Pseudogymnoascus destructans'' which colonizes the bat's skin. No obvious treatment or means of preventing transmission is known,〔(【引用サイトリンク】first=Julia )〕 and some species have declined >90% within five years of the disease reaching a site. The US Fish & Wildlife Service (USFWS) has called for a moratorium on caving activities in affected areas and strongly recommends to decontaminate clothing or equipment in such areas after each use. The National Speleological Society maintains an up-to-date page to keep cavers apprised of current events and advisories.〔(【引用サイトリンク】url=http://www.caves.org/WNS/ )〕 ==Impact== white nose syndrome was estimated to have caused at least 5.7 million to 6.7 million bat deaths in North America.〔 In 2008 bats declined in some caves by more than 90%,〔 Alan Hicks with the New York State Department of Environmental Conservation described the impact in 2008 as "unprecedented" and "the gravest threat to bats...ever seen." eleven bat species, including three endangered species and one species proposed for endangered species listing have been affected by WNS or exposed to the causative fungus, Pseudogymnoascus destructans, with impacts varying widely.〔(【引用サイトリンク】title=Bats affected by WNS )〕 As of 2012 four species have suffered substantial declines and extinction of at least one species was predicted.〔 Declines included species already listed as endangered in the U.S., such as the Indiana bat, whose hibernaculum in many states has been affected. The once-common little brown bat has suffered a major population collapse in the northeastern U.S. In 2012 the northern long-eared myotis ("Myotis septentrionalis") was reported to be extirpated from all sites where the disease has been present for >4 years.〔 In 2009, the Virginia big-eared bat (''Corynorhinus townsendii virginianus''), the official state bat of Virginia,〔("Cute but contagious" ) ''The Economist'', May 21, 2009〕 and the Gray bat had yet to suffer measurable declines. Beyond the direct effect on bat populations, WNS has broader ecological implications. The Forest Service estimated in 2008 that the die-off from white-nose syndrome means that at least 2.4 million pounds of insects (1.1 million kg) will go uneaten and become a financial burden to farmers, possibly leading to crop damage or having other economic impact in New England. In 2008, comparisons were raised to colony collapse disorder, another incompletely understood phenomenon resulting in the abrupt disappearance of Western honey bee colonies,〔 and with chytridiomycosis, a fungal skin disease linked with worldwide declines in amphibian populations.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「White nose syndrome」の詳細全文を読む スポンサード リンク
|
