White-nose syndrome – bat disease
A disease known as White-nose Syndrome is spreading through the world’s bat colonies and killing off millions of animals. in fact, in North America, it is has become so serious as to potentially cause local or national extinction of several bat species, including the lovable Little Brown Bat [Myotis Lucifugus].
What is this disease?
White-nose syndrome is caused by a fungus known as geomyces destructans. It is a fungus which thrives in dark, damp conditions in rock crevices and caves – ideal locales for bats. The fungus grows on the bat’s noses, wings and ears. This appears to make the hibernating bats restless during winter, causing them to stir and even wake & fly around, when they should be hibernating. This causes them to use up their stored winter fat reserves which get the creatures through the otherwise food-free winter months.
Once the fugal infection infects a colony, it appears to spread fast through the hibernating colony, and on average kills 73%, according to a research team which reported in the December 2010 edition of the journal Science. They studies Little Brown Bats in north eastern US, gathering 17 years’ worth of data on bat colonies.
The disease was first discovered in a commercial tourist cave related to bat observation in New York state in 2006. this cave was frequently visited by tourists, which is why scientists believe that humans carried the original fungal spores into the cave.
Where can the disease be found?
Currently, the fungus has been located in many parts of Europe, and areas of North america, primarily Pennsylvania, New York state and new England. Recent research appears to suggest that the fungus has been resident within europe and has periodically infected several bat populations for many years before its more deadly infections in the US more recently. Also, the fungal disease appears to have a less deadly impact on Europe’s bat populations, with far smaller mass die-offs in the populations.
Researchers are currently trying to determine the reasons for this difference. one reason is proposed to be that many of the european bat species are larger, and thus their hibernations are less easily disrupted. another suggestion, is that european bat colonies are smaller and their populations are less concentrated, thus slowing or reducing the fungal disease impact.
What does the future hold?
Scientists have only just begun to study the fungal impact and longer term effects on bat colonies. also, only a few species have been studies. notably the little Brown Bat of eastern US. Yet other North American species such as the northern long-nosed bat and the tri-coloured bat are also known to be infected – suggesting the disease is far more widespread in its impacts than presently known.
Currently, colonies and entire local populations are dying off at such a rate, that some predict local extinctions over the next 15 years; if no recovery period or resistance occurs.
Is this disease unique? NO
So what is happening here? is this new disease unique? Unfortunately not, as it is already being likened to the sudden appearance of the chytrid fungus which is decimating many amphibian populations and believed to have caused several species extinctions. Also, the sudden appearance of the Devil Facial Tumor disease, an infectious cancer threatening Tasmanian devils of Australia, has has devastating impacts on the species’ population.
Can we do anything to help?
Several research teams from The US, continental Europe and the UK are currently researching the causes, impacts and effects on their local bat populations, whilst trying to identify colonies with any genetic resistance to the disease. But all work is in the early stages.
The scientists are encouraging people to install bat boxes in their homes/gardens and local parks. These can have several benefits, by slowing the spread of the disease by spreading and splitting the colonies and populations, boosting chances of survival and creating a lower moisture habitat which are less formative to fungal development.
The 'bad bat' reputation is unjustified!
People may ask ‘why should we care?’. well consider the fact that a single bat can eat half its body weight in insects in one night, and most of these insects we consider annoying or deadly agricultural pests causing billions of dollars/euros/pounds of costs. so the past year’s deaths of over one million bats in the eastern US alone could account for almost 700 tonnes of insects and multi-millions in financial impacts!
Yet bats are still unfairly tarnished with a reputation for anything from infecting humans with rabies and blood sucking vampires terrorizing populations. Neither of these are relevant or true towards humans.
In the US, UK and several countries in continental Europe Bat Conservation Trusts and other bodies are raising awareness of the condition in bat populations.
Although as yet, no infection has occurred in the UK, the organisation has even produced a guide on their web site, and advise on how to record cases and sent the data.
All organisations state that if you see live or dead bats with white fungal infactions around the head, please do not touch them. This could spread the disease. Where possible note any details and take a phot, and inform the authorities. In the UK the Bat Conservation Trust contact number is 0845 1300 228.
Releted sites for information.
www.nwhc.usgs.gov › Disease Information