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Die-off of bats could hurt area crops
http://www.boston.com/news/local/massachusetts/articles/2008/02/07/die_off_o
f_bats_could_hurt_area_crops/

Mystery illness hits caves in Vt., N.Y.

By Beth Daley, Globe Staff | February 7, 2008

A mysterious illness is sickening and killing
thousands of hibernating bats in New York and
Vermont, baffling scientists who fear that tens
of thousands more may be dying in abandoned mines
and dark caves throughout the Northeast.

Humans are not believed to be at risk from the
disease, but the death of large numbers of bats
could indirectly affect New Englanders: Bats
devour crop pests, midges, and mosquitoes.

"I've studied bats for 40-something years, and
I've never seen anything like this; it's
alarming," said Thomas Kunz, a preeminent bat
researcher at Boston University. "It's
frustrating and perplexing, because we don't know
what it is and we don't know how to control it."

The US Fish and Wildlife Service warned the
public in the last week to keep out of caves and
mines in New York and Vermont because humans
might be inadvertently spreading the unknown
pathogen. The National Speleological Society has
closed all caves it owns in New York and
Pennsylvania, and other caving organizations have
urged people to avoid places where bats may hibernate in the Northeast.

No dead or diseased bats have yet been found in
Massachusetts, but state officials are organizing
an expedition in coming weeks to look for sick
bats in four long-closed Western Massachusetts
mines. Those mines are off-limits to the public,
and bats hibernate in only a few tiny caves in
the state, mostly on private land.

The disease was first discovered in a cave near
Albany, N.Y., in January 2007 and was soon found
in three more within 7 miles. In March, officials
at the New York Department of Environmental
Conservation determined that as many as 11,000
bats had died from the disease, dubbed "white
nose syndrome" because of a flaky white fungus on
the nose of many of the sick and dead bats.

Scientists do not yet know if the fungus is a
cause of the illness or an effect. Some of the
sick bats behaved oddly, clustering near the
entrance of New York caves, flying in winter when
they should have been sleeping and crashing into snow banks.

Scientists hoped that last year's outbreak was an
anomaly. But in the last two weeks, it has become
clear that the disease has returned and is
spreading. Sick bats have now been found in caves
135 miles apart. Sick bats have been seen again
in the original four caves, plus four others in
New York, including one discovered yesterday.
Bats in a western Vermont cave are also sick.

Researchers have found a small number of dead
bats this year. But based on last year's
experience, they expect many more to succumb around March.

Scientists say they are extraordinarily concerned
because the disease is already affecting four
species - including the Indiana bat, recognized
by the federal government as an endangered
species - and mortality has reached as high as 97
percent in some caves. In one New York cave, the
population crashed from 1,300 bats several years ago to 38 this year.

"If we assume only 50 percent decline at the new
sites, we are talking hundreds of thousands of
bats that could die," said Alan Hicks, a bat
specialist with the New York Department of Environmental Conservation.

Bats hold great ecological importance worldwide.
In addition to feeding on insects, they pollinate
plants in many places and disperse seeds, though
not in New England. The animals can live longer
than 30 years and generally have only one
offspring a year, meaning that it would take many
years for the population to rebound if it crashed.

While overall bat numbers in New England are hard
to estimate, scientists say the nine bat species
here probably number in the hundreds of
thousands. Three of the species are migratory and
leave in the winter, while others hibernate in
old mines or in a line of limestone caves
stretching north from the Berkshires through
western Vermont and into adjacent New York. Some
big brown bats, as many homeowners know, find a warm winter home in
buildings.

Vermont officials examined four bat caves last
week and did not see diseased animals, but will
investigate more caves in the next two weeks.
Similarly, in New Hampshire, which has smaller
groups of bats, officials investigated four mines
in recent weeks and found no evidence of disease.

More than a dozen government and university labs
across the country are trying to determine the
cause of the problem. So far, scientists have
just a few tantalizing clues: They know that
affected bats are using up fat reserves far
earlier in the winter than normal, possibly
because they are responding to the disease. Some
of the bats also appear to be exhibiting symptoms similar to pneumonia.

"But really we have no idea what is causing it yet," Hicks said.

He said scientists don't even know whether the
disease is spread by bats or by humans who visit
the caves and mines. If bats are transmitting the
disease, hibernating groups are particularly
vulnerable, because they are in such close
quarters. Often 300 animals are packed per square foot.

Researchers want to find out whether other
colonies will become infected once bats of all
species come out of hibernation this spring and
disperse to their maternity roosts. Bats also
travel great distances, wintering in Vermont, for
example, but summering in Rhode Island, increasing the transmission risk.

Bolstering the theory that humans are spreading
the disease is the fact that most of the infected
populations have been found in caves or mines
popular with cavers, with the exception of
infected bats in the cave discovered yesterday.

Cavers say they will avoid caves until more is
known about the disease. "Our goal is to find out
any way cavers, through action or inaction, can
help to prevent any further problems or assist in
protecting the bats in the region." said Emily
Davis, office manager of the New York-based
Northeastern Cave Conservancy Inc., a nonprofit
cave land trust that is holding an emergency
meeting Sunday about the issue. Members "are
willing to curtail the caving if it will help the
bat populations," she said.

Bat specialists say they do not believe the
request to stay out of caves should be extended
to tourist attractions, because so few
hibernating bats are in places where people visit.

Kunz and other scientists will be entering New
York caves next week, using respirators and
dressed in plastic suits that will be
decontaminated afterward to make sure they don't
spread the disease. They will draw bat blood to
analyze the animals' immune systems.

They will also use thermal cameras: Because bats
use so little energy when they are hibernating,
if their bodies give off more heat than expected,
it may indicate they are using up energy reserves
and are afflicted with the disease.

"There is a lot we don't know," said Scott
Darling, a wildlife biologist with the Vermont
Fish and Wildlife Department. "There is a real threat."