Submitted by
Editor on
Fri,
12/18/2009 -
1:03pm.
Chris Torres
Staff Writer
Having read
reports of
dying bats
in
New
York and New
England,
DeeAnn
Reeder
feared that
Pennsylvania
could be
next on the
radar.
Her fears
were
realized
just before
Christmas
last year
when she was
conducting a
survey of
bats in an
old,
abandoned
mine in the
northern
part of the
state.
“My heart
just sank.
We knew we
had it.”
She found
hibernating
bats covered
in a
mysterious
white fungus
and others
on the
ground,
dead.
“It is a
mystery,
really.”
Since 2006,
this mystery
known as
white-nose
syndrome has
been playing
out in New
York State
and New
England,
where it is
believed
more than 1
million bats
have died
from the
ailment.
Now it is in
Pennsylvania,
where it has
spread to
sites across
the
northcentral
and
northeastern
part of the
state.
With 4,000
mines and
1,000 known
caves in the
state, a
major
breakout
here could
be
catastrophic.
The symptoms
are
puzzling. A
mysterious
white
fungus,
which has
never before
been
identified,
is showing
up on
seemingly
healthy bats
hibernating
in caves and
mines.
These same
bats are
emerging
weeks
earlier from
their caves,
looking for
food and
eventually
dying of the
cold
weather.
But what is
causing all
of this? Is
it the
fungus
itself? Are
bats immune
systems
becoming
more
susceptible
to disease,
just like
what has
happened to
bees with
colony
collapse
disorder?
Researchers,
like Reeder,
still don’t
know the
answers.
What is
known is
that bats
are some of
the best
insectivores
out there.
One small
bat can
consume its
entire
weight in
insects
during one
night of
feeding.
With the
ailment now
spreading to
West
Virginia and
Indiana, it
is feared
that
millions of
bats could
potentially
die as a
result,
possibly
leaving
behind
lasting
effects on
agriculture
and the rest
of the
ecosystem.
What is the
killer?
The fungus
that causes
white-nose
syndrome was
identified
in the
January
issue of the
journal
Science. It
is part of a
genus of
fungi known
as Geomyces,
which grow
in cold
temperatures
and prefer
damp
conditions,
the kind you
would find
in a cave or
abandoned
mine. Ideal
temperatures
range
between 41
and 50
degrees
Fahrenheit.
It has been
given the
scientific
name
Geomyces
destructans.
The lead
researcher
of the
published
paper, David
Blehert, a
microbiologist
at the U.S.
Geological
Service’s
National
Wildlife
Health
Center in
Madison,
Wis., said
the fungus
was
identified
after dead
bat samples
from all
over New
York and New
England were
sent in to
the lab.
Unlike other
types of
Geomyces,
this
particular
type of
fungus has
never before
been
identified,
according to
Blehert.
But reports
have since
surfaced of
a similar
type fungus
being
reported in
Europe as
far back as
the 1980s on
species of
bats in that
region. The
only
difference
is that
those bats
did not die
from it.
Bats don’t
migrate from
North
America to
Europe or
vice versa,
Blehert
said, which
leads him to
believe the
fungus was
inadvertently
introduced
by a human
or other
animal into
a cave.
His lab is
working on
identifying
the genetic
origin of
the fungus
and whether
or not it is
causing the
deaths.
Blehert said
many signs
point to the
fungus being
the cause of
the deaths.
“It
certainly is
not as
common as
viral
infection,
but fungi
are very
common
pathogens of
cold-blooded
animals,” he
said,
pointing out
that bats
are both
cold- and
warm-blooded
since they
literally
shut down
their bodies
to go into
hibernation
over winter
and their
body
temperature
decreases
dramatically.
Connecting
the dots
Along with
the white
fungus
showing up
on the noses
and bodies
of infected
bats, many
are leaving
their
hibernacula
(hibernation
area)
several
weeks before
they are
supposed to
and are
starving to
death.
Reeder,
assistant
professor of
biology at
Bucknell
University
in
Lewisburg,
Pa., has
been on the
case of the
mysterious
white-nose
syndrome
ever since
it first
appeared in
Pennsylvania
in 2008.
“There is a
lot we just
don’t
understand
and the
problem is
we don’t
know enough
about bats,”
Reeder said.
There are
nine bat
species in
the state.
Five have
been found
to be
susceptible
to white
nose
syndrome,
including
the little
brown bat
and the
Indiana bat,
which is
classified
as an
“endangered
species.”
Big brown
bats, which
Reeder said
are known as
the
“farmer’s
friend,”
have not
been
impacted as
much, which
only adds to
the mystery
of the
malady.
She has been
testing the
theory that
if the
fungus is
not killing
the bats,
maybe it is
leading the
bats to
starve to
death during
hibernation.
Healthy bats
typically go
into
hibernation
with enough
body fat
from their
feeding
season to
hold them
over until
spring. They
can get
aroused
every 15 to
20 days
throughout
the winter,
she said,
typically to
get rid of
waste.
Each time
they get
aroused, she
said, they
can lose up
to two
months of
their stored
body fat
because
their bodies
warm back
up, using a
lot of
energy to do
it.
A test was
done this
past year at
13 sites in
six states
to see the
arousal
patterns of
bats
suspected to
have
white-nose
syndrome.
Data
monitors
were placed
on 450 bats.
The results
indicated
that bats
with the
syndrome
ended up
being
aroused
every four
to five
days, which
Reeder said
indicates
that the
bats are
being
bothered to
the point
where they
are waking
up when they
should be
hibernating.
It could
explain why
she has
received
reports of
bats flying
outside of
caves and
mines in the
middle of
January and
February,
searching
for food and
eventually
dying as a
result of
the cold
weather.
Another
factor that
complicates
things is
the fact
that these
bats have
been found
with
weakened
immune
systems.
One of the
original
hypotheses
as to the
cause of the
deaths was
possibly the
bats being
exposed to a
plethora of
chemicals
like
pesticides
that over
time weaken
immune
systems. But
not enough
evidence,
she said,
has been
found to
support this
theory.
Mammal
hibernators,
she said,
tend to have
weakened
immune
systems
because
their body
temperatures
decrease
during
hibernation.
This winter,
several
caves are
being
monitored by
infrared
camera to
see what
behavior the
bats exhibit
when they
are infected
with white
nose
syndrome.
“It really
is about
connecting
the dots at
this point.
You can
clearly say
that the
arousal
patterns are
not normal,”
she said.
“So you have
this fungus
growing on
you, so how
does this
translate
into warming
up?”
Impacts
beyond
deaths
Whatever the
reason for
their
deaths, the
impact bats
have on the
ecosystem is
something
that is
coming to
light as a
result of
their
decline.
“Bats are
the primary
predators of
nocturnal
insects in
the
U.S.,” said
Mike Gannon,
professor of
biology who
studies bat
ecology at
Penn State
Altoona. “As
a result,
they are a
keystone
species.”
In other
areas of the
world, such
as the
Caribbean
and South
America,
Gannon said
bats act as
pollinators.
Here, they
eat insects
and a lot of
them. They
include
insects such
as the corn
borer moth
and cucumber
beetle, two
of the most
invasive
crop insects
out there.
“Bats
perform what
we call an
‘eco
service.’ (A
bat) can eat
up to 100
percent of
its body
weight when
it is
feeding,”
Reeder said.
There are
many
published
reports that
try to
quantify the
value of
bats on
farms, but
most of
those
reports
focus on
bats in
other parts
of the
country,
mainly
Texas.
Still, it
does give a
glimpse into
the value of
bats on
farms.
The
Ecological
Society of
America in
2006
published a
report on
the value of
Brazilian
free-tailed
bats on
cotton
fields in
eight
counties in
Texas.
The report
showed the
value of the
bats as a
pest control
is around
$741,000 per
year on
average,
with a range
between
$121,000 and
$1.725
million. The
value of the
cotton
harvest in
these eight
counties in
southcentral
Texas, the
report
states,
ranges
anywhere
between $4.6
million and
$6.4 million
per year.
A 2000
report
authored by
Sheryl
Ducummon for
Bat
Conservation
International
found the
little brown
bat can eat
up to 1,200
mosquito-sized
insects in
one hour.
The report
also found a
colony of
150 big
brown bats
can eat
enough
cucumber
beetles in a
given summer
to protect
farmers from
33 million
of those
beetle’s
larvae.
A consensus
statement
released at
the second
White-Nose
Syndrome
Emergency
Science
Strategy
Meeting held
this past
May in
Texas
states that
the number
of insects
eaten by 1
million bats
is equal to
694 tons.
Bats are
particularly
important in
organic
systems,
where
farmers are
not only
encouraged
but required
to provide a
safe place
for the
critters to
consume
their food.
“There is a
requirement
that organic
farmers must
have
biodiversity
on their
farms. So
they have to
provide or
maintain
housing for
bats and
birds,” said
Leslie Zuck,
executive
director of
the
Pennsylvania
Certified
Organic
Program.
"It’s also
part of the
whole
concept of
having a
good
ecosystem.
So organic
farmers
invite
things that
other
farmers will
not want to
have.”
Bats are
also a big
player in
integrated
pest
management (IPM)
systems.
“A lot of
the pests
that we deal
with are at
least in
part
controlled
by things in
nature,”
said Ed
Rajotte,
coordinator
of the
state’s IPM
program at
Penn
State. “It
is becoming
more
important as
pesticides
are becoming
more
restrictive
and less
broad
spectrum
than they
used to be.”
Preventing
the spread
With few
answers as
to why white
nose
syndrome is
spreading
and what is
causing it,
it has been
difficult
for
researchers
to come up
with ideas
as to how to
stop it from
spreading.
The U.S.
Fish and
Wildlife
Service has
recommended
closing all
caves and
mines to
human access
within 250
miles of an
area
affected
with
white-nose
syndrome.
The
Pennsylvania
Game
Commission
has a list
of
guidelines
for
reporting
sick bats
and for
researches
handling
sick bats.
The U.S.
Department
of the
Interior
appropriations
bill passed
on Oct. 30
contained
$1.9 million
for
research,
monitoring
and related
activities
to respond
to white
nose
syndrome.
But is it
enough?
Given the
number of
bats that
have already
died, the
long-term
damage could
already be
done.
“When you do
anything
like this to
the
ecosystem,
you will
have ripple
effects,”
Reeder said.
“It will
cause a
profound
change.”
