By Dr. Merlin D. Tuttle,
Honorary Ambassador for the Year of the
Bat campaign
Bonn, 21 January 2011 - Were you aware that
bats are key pollinators in many parts of
the world? Pollination is a vital ecosystem
service without which many of our key industries
such as agriculture and pharmaceuticals
would collapse or incur heavy costs for
artificial substitution. TEEB has found
that in some estimates, over 75% of the
worlds crop plants, as well as many plants
that are source species for pharmaceuticals,
rely on pollination by animal vectors
Furthermore, for 87
out of 115 leading global crops (representing
up to 35% of the global food supply), fruit
or seed numbers or quality were increased
through animal pollination. Bats also provide
a wide range of ecosystem services which
benefit mankind from insect deterrent to
bat guano fertilizer.
Bat Pollinators: Tequila
and the Tree of Life
More than 1,200 species
of bats comprise nearly a quarter of all
mammals, and their ecological services are
essential to human economies and the health
of whole ecosystems worldwide. Without bats,
costly crop pests would increase, forcing
greater reliance on dangerous pesticides.
We could also lose some of our favorite
foods and beverages and suffer the consequences
of greatly diminished biodiversity.
Many of our most important
foods come from bat-dependent plants. These
include bananas, plantain, breadfruit, peaches,
mangos, dates, figs, cashews and many more.
In fact, in an average tropical food market,
approximately 70 percent of the fruit sold
comes from trees or shrubs that rely heavily
on bats in the wild. Some such as the famous
durian, still rely on bat pollinators even
in commercial orchards. This king of Asian
fruits sells for a billion dollars annually,
but could be lost without healthy populations
of its bat pollinators.
In East Africa nectar
feeding bats are essential to fruit production
of the Baobab tree, sometimes referred to
as the African Tree of Life due to the exceptional
variety of wildlife that depend on it for
food and shelter. Recently, it has additionally
become known as the Vitamin Tree. Baobab
fruits contain six times as much vitamin
C as oranges, twice as much calcium as milk,
are rich in other vitamins and antioxidants
and may soon become a billion dollar a year
crop.
In deserts, from the
southwestern United States to southern Peru,
more than 100 species of cactus and agave
plants rely on bats for pollination. Giant,
columnar cactus plants, such as the famous
saguaro and organ pipe, are heavily relied
on for food and shelter by a wide variety
of birds and mammals, and agaves are extremely
useful in erosion control, as ornamentals
and as the source of all tequila liquor.
The world's thirsty Margarita drinkers can
definitely raise a glass in praise of bats.
Bats: Nature's natural
pesticide
Bats also provide an
essential ecosystem service known as "biological
control." Natural pests and diseases
are usually regulated by a wide range of
predators and parasites. TEEB has found
that agricultural pests cause significant
economic losses worldwide. Globally, more
than 40% of food production is being lost
to insect pests, plant pathogens, and weeds,
despite the application of more than 3 billion
kilograms of pesticides to crops, plus other
means of control. Natural control of pests
is to date one of the most effective means
of dealing with these threats. Bats are
essential predators which keep many damaging
insects from destroying crops.
The colony of 20 million
free-tailed bats that lives in Bracken Cave
near San Antonio, Texas, for example, consumes
200 tons of insects nightly, predominantly
crop pests such as corn earworm and armyworm
moths. Just one of these bats can catch
enough moths in one night's feeding to prevent
50,000 or more eggs from being laid, resulting
in local cotton growers saving close to
a million dollars annually in reduced need
for pesticides.
A single mouse-eared
bat (widespread in Europe and North America)
can capture 1,000 or more mosquito-sized
insects in just one hour. A colony of 150
big brown bats, a number that could live
in a backyard bat house, can capture enough
cucumber beetles in a summer to prevent
them from laying 33 million eggs that would
otherwise hatch into corn rootworms, a billion-dollar-a
-year pest in the United States.
In many locations, bats
can be easily attracted to bat houses to
help protect gardens and organic farms.
Outstanding success has been reported from
Oregon to Georgia in the United States,
probably because many of our worst insect
pests listen for bat echolocation signals
and flee areas where bats are heard. A pecan
grower in Georgia reports having become
entirely organic since he attracted thousands
of bats to extra large bat houses in his
orchard. So the next time you think organic,
think "bats."
Bat Fertilizer
Bats are also the primary
energy producers for many cave ecosystems.
Guano deposits beneath their roosts provide
energy that sustains thousands of unique
life forms, from bacteria and fungi to arthropods
and small vertebrates. These organisms are
often endemic to a single cave or cave system,
but provide a potential treasure trove of
biodiversity needed for solving human problems,
from production of new antibiotics and gasohol
to improved detergents and waste detoxification.
Additionally, extraction
of bat guano for fertilizer provides an
invaluable renewable resource for whole
communities in developing countries from
Asia and Africa to Latin America. For example,
due to this eco-service of bats, Thailand's
Khao Chong Pran Cave has become a major
source of income for the local community,
as well as a unique tourist attraction.
Careful protection and harvest management
have allowed annual guano sales to increase
from $10,000 to $135,000. Bat guano is big
business.
From Terror to Tourist
Attraction
As people learn to appreciate
bats, these fascinating animals are paving
the way for popular tourist attractions.
When 1.5 million free-tailed bats began
moving into crevices beneath the Congress
Avenue Bridge in downtown Austin, Texas,
health officials warned that they were rabid
and dangerous, and local people wanted the
bats eradicated. However, through the educational
efforts of Bat Conservation International,
fears were calmed, and in more than 30 years,
not a single person has been harmed. The
bats consume roughly 15 tons of insects
nightly and attract 12 million tourist dollars
each summer, clearly demonstrating the value
of bats to our environment and economies.
Year of the Bat 2011-2012
Unfortunately, many
people in other locations around the world
still misunderstand, fear and persecute
bats at great harm to themselves. Too many
have heard only of vampires and disease,
both of which have been greatly exaggerated
by sensational media stories.
Needlessly fearful humans,
in Latin America, have mistakenly destroyed
thousands, even millions of highly beneficial
bats at a time by sealing, burning or poisoning
roosts, especially in caves, and many more
bats have been lost through simple neglect
of their conservation needs.
Ironically, even the
common vampire bat of Latin America has
proven useful. A new drug, Desmoteplase
developed from research on vampire saliva,
appears to greatly improve treatment of
stroke victims, a potentially enormous contribution
to human wellbeing. Who would have thought
that a bat - and a vampire, at that - could
help save countless lives?
Year of the Bat (2011-2012)
celebrations will highlight bat values and
needs, providing unique introductions to
these incredibly fascinating animals that
unfortunately rank among our planet's least
understood and most rapidly declining and
endangered animals. But as more people learn
about and account for the ecosystem services
provided by bats, greater conservation efforts
will be made to ensure the survival of these
fascinating and essential creatures.
For more information:
Year of the Bat 2011
- 2012 is a global campaign to promote conservation,
research and education about the world's
only flying mammals. Year of the Bat is
supported by the United Nations Environment
Programme, the Convention on the Conservation
of Migratory Species and EUROBATS, as well
as numerous partner organizations around
the world.
Additional information
for this article was provided by The Economics
of Ecosystems and Biodiversity (TEEB).
