Just a few of the estimated two million bats still hanging around in the National Museum's roof ... but for how much longer?
HE USE of pesticides in the roof area of the National Museum in Phnom Penh has launched
a storm of protest from bat conservationists concerned about the safety of the huge
bat colony that calls the museum home.
Museum officials have admitted using a combination of pesticides, including DDT,
angtrin and asotrin, in the roof area of the museum over the past year to control
fleas and ticks carried by the bats.
"We don't want to kill the bats, we just want them to go away somewhere ...
if we wanted to kill them we could do it in half an hour," National Museum Director
Khun Samen told the Post.
"Cambodia only has one National Museum ... Why are there a million bats living
here? This isn't the bat museum."
However, observers and bat conservationists blame the use of the pesticides on marked
reductions in the size of the colony as measured by recent flyouts of bats from the
museum at dusk.
"The use of DDT, and angtrin or asotrin to try to rid the museum of bats is
particularly disturbing because [these] are highly toxic organophosphorous insecticides
with a long history of wildlife kills," said Barbara French of the organization
Bat Conservation International by email.
"Both acute oral and dermal toxicities are very high for both birds and mammals."
French warns that museum workers, who have long harvested bat guano for sale as a
fertilizer and bats themselves as the key ingredient in a bat-meat soup, are also
at risk from the pesticides.
"Serious poisoning could result from ingestion of these chemicals," French
said. "Also, if applied in a closed space where it would not be exposed to normal
weathering, toxic effects from these chemicals would probably last for quite some
time, exposing people as well as bats to dangerous chemicals."
The origin of the National Museum's bat colony is one of the less-malign influences
of the Khmer Rouge era, when bats began roosting in the empty museum after the evacuation
of Phnom Penh in April, 1975.
By 1993, Australian bat researcher Greg Richards estimated that approximately two
million bats lived in the museum, including a previously unknown species subsequently
christened the Cambodian Freetailed bat.
French claims that the size and composition of the museum's bat colony makes it uniquely
"...Large bat colonies the size of this one are not common," French said.
"The few that do exist have been used in other parts of the world as successful
tourist attractions that have proven important sources of revenue for those regions."
For Samen, however, the existence of the bats within the National Museum poses an
unacceptable risk to both the integrity of the priceless artworks on display and
to the health and comfort of the museum's employees and visitors.
"People care about the bats, but they don't care about the artifacts in the
museum," he said. Pointing to a large ornamental cupboard in the corner of his
first floor office, Samen added, "We can't exhibit this cupboard in the museum
... It would be destroyed by the acidity in the bat guano and urine that falls into
the museum gallery."
Indeed, a short tour of the gallery indicates large quantities of bat guano on all
surfaces, and discolored streaks of bat urine staining the walls.
"We must be constantly cleaning the bat guano and urine off the artwork,"
Samen said, eyeing the shoulders of an Angkorian statue for signs of droppings.
Samen says that more immediate and painful reminders of the bat colony's presence
in the museum are the fleas and ticks that slip through the ceiling onto hapless
visitors and employees below.
"If we don't use insecticide [in the roof area], there are so many fleas that
museum staff can't stay in the gallery," Samen fumed. "Visitors often put
on Vietnamese-style hats in the museum [because of the flea and tick threat]...in
the National Museum of Cambodia such behavior is unacceptable."
Samen is not the first person to raise the potential health threat of the museum's
bat colony. In 1995 the Tropical Medicine Division at Fairfield Hospital recommended
that museum workers be vaccinated against both rabies and bubonic plague.
In 1995 a custom-built "second ceiling" was added between the bat roosts
and the original ceiling and was specifically designed to contain any waste produced
by the bats.
However, Samen says that the "second-ceiling", built with $500,000 of Australian-donated
funds, has failed miserably.
"[The ceiling builders] didn't think about the leaks and other problems created
by the bats," he said. "That's why fleas always fall on people."
Barbara French acknowledges that the "second ceiling" has failed to live
up to expectations, but adds that the museum has alternatives to using pesticides
against the bats.
"It is our understanding that the work [on the second ceiling] was not carried
out as recommended ... and so the leaking roof continues to cause problems,"
French said. "It is also our understanding that the French International Association
of Mayors (AIMF) has offered to pay some of the cost of repairing the roof."
According to Samen, the AIMF plan has inexplicably stalled, leaving the use of pesticides
his only alternative.
The National Museum, beside the Royal Palace in Phnom Penh
Denying any recent use of DDT ("We used a small quantity of DDT last year and
only one time," Samen assured the Post) Samen says the pesticides are used only
on the floor area below the bats. "How can we kill the bats with just the smell
However, a worker who led Post staff to the roof area to view the bats explained
that angtrin was used on the floor area, while DDT was used to soak bundles of rags
hung in the eaves of the roof where the bats roost.
Questioned about a reported decline in the size of the bat colony, Samen attributed
it to an annual "die-off" of young bats during the rainy season.
If pesticides truly are affecting the health of the museum's bat colony, French says
the effects will be far-reaching.
"By a conservative estimate ... this particular colony of bats consumes 17,000
kilograms of insects a night," French said. "The loss of these bats would
most likely increase the need for chemical pesticides, increasing the cost of agricultural
production, with toxic run-off eventually polluting the Mekong River and its fish
Rubbing a welter of flea bites on his ankle and looking mournfully at the ornamental
cupboard that he fears museum visitors may never see, Samen insists that the bats
"If people are really concerned about the bats, why don't they build another
structure for them to live in?" he asks. "Why don't people care about the
artworks in the museum and the more than eighty employees who can't go in the gallery
because of all the fleas from the bats?"