A deadly white-nose fungus has killed some 6 million bats in the past 5 years across the USA and Canada, and the trend looks set to rise.
The US Fish and Wildlife Service have announced that there is a growing trend in number of bat deaths across America. According to scientific estimates, around 6 million bats have been killed by a contagious fungus. The Huffington Post, picking up on January's announcement about a rise in bat deaths, reports data which suggest that the fungus has a mortality rate of 100%.
Six different species of bat have been affected, with the brown bat (Myotis lucifugus) hit hardest in recording the largest number of death. In an earlier statement the US agency describes the bat deaths as "the worst wildlife health crisis in memory".
The cause of the bat deaths is a type of fungus which grows as a white substance on the nose of bats and quickly kills them (hence the common name 'white-nose fungus'). As yet there is no known cause of the pathogen. To date the pathogen has been detected in 16 US states and four Canadian provinces.
The first cases were identified in New York state in 2006 (in a cave in Schoharie County, New York). In that year researchers from the Center for Ecology and Conservation Biology found several dead bats white fungus on their muzzles and other parts of their bodies. The bats also had very low body fat. The Scientist describes the fungus by its Latin name: Geomyces destructans, and describes it as a cold-loving fungus. The fungus also cause unusual behavior, with infected bats seen flying outside during the day in temperatures at or below freezing (bats typically hibernate in caves during cold spells).
In a press release, the Director of the Fish and Wildlife Service, Dan Ashe said: “This startling new information illustrates the severity of the threat that white-nose syndrome poses for bats, as well as the scope of the problem facing our nation. We are working closely with our partners to understand the spread of this deadly disease and minimize its impacts to affected bat species.”
Professor Rick Adams of University of Northern Colorado, who has compiled 13 years of data on bat populations, has described the decline in bat populations as linked to climate change and hence a matter of major ecological concern.
One interesting theory, from Bat Conservation International, about the fungus is that it may have come from Europe, transported by tourists to the U.S. and Canada. European bats appear to have an immunity against the fungus.
2012 may need to become 'year of the bat' if the further decline in the North American bat population is to be prevented.