Nairobi, 5 April 2012
- In just over two months, representatives
from world governments will be winging their
way to the Rio+20 conference in Brazil to
map out the future path of sustainable development.
Supporting ecosystem
services (the benefits people gain from
healthy ecosystems) is a key part of the
transition to a low-carbon, resource efficient
Green Economy, which in the context of sustainable
development, is one of Rio+20's major themes.
One winged, nocturnal
resident of Mexico with strong Brazilian
roots is demonstrating just that - and boosting
the US cotton industry by hundreds of thousands
of dollars in the process.
In summer months, the
Brazilian free-tailed bat migrates from
its habitat in central Mexico to breeding
grounds in the north of the country and
south western areas of the United States,
where it feeds on moths and other agricultural
pests.
A study published in
the journal Frontiers in Ecology and the
Environment estimates that this natural
pest control has an economic value of US$1000,000.
The study takes into
account the value of cotton crops that would
have been lost in the absence of bats and
cost savings made through the reduced use
of pesticides.
During the UN-backed
Year of the Bat 2011-12, the UNEP Convention
on the Conservation of Migratory Species
of Wild Animals (CMS), emphasizes the value
of ecological services bats provide to human
economies and the health of ecosystems.
"Bats perform an
essential role as an agent of natural pest
control by generating economic, social and
environmental benefits in a Green Economy,"
said CMS Acting Executive Secretary Elizabeth
Maruma Mrema.
Migratory species including
bats can provide biological solutions to
increase economic gains while reducing harm
to the environment.
Rio+20 provides the
opportunity for countries to enhance efforts
towards restoring and boosting the health
of ecosystems globally in order to deliver
growth, generate employment and maintain
services such as water supplies to the health
of agricultural systems.
Brazilian free-tailed
bats (Tadaridabrasiliensis) can form huge
summer breeding colonies, which can reach
10 million animals. The total population
of the colonies in the region can surpass
100 million bats in each season.
By consuming the adult
moths of highly destructive agricultural
pests such as the corn earworm, cotton bollworm,
fall armyworm and tobacco bud worm, these
bats provide a previously unaccounted pest
control service in cotton production.
As predators, bats are
very efficient at eliminating the pests
over a wide area. Once bollworm moths start
emerging in the cotton fields, bats increase
their foraging activities at night.
A single female Brazilian
free-tailed bat consumes eight grams of
adult insects every night, which is about
two thirds of her body weight. Up to 20
adult bollworm moths are eaten by a single
bat each night.
A single bat that consumes
1.5 adult female moths per night prevents
five larvae from damaging crop plants. On
the other hand, a larva destroys up to three
bolls (the protective capsule in which cotton
grows) during its lifetime. During the peak
growing season in June, when cotton plants
are highly susceptible to external damage,
a single bat could even prevent a damage
of up to 10 bolls at night. To produce a
pound of seed cotton 120 bolls are required.
In the study area, the
Winter Garden region of South Texas, farmers
apply pesticides throughout the month of
July, the time when the maximum density
of bollworm larvae is reached. Although
pesticides kill close to 100 per cent of
the eggs and almost 90 of the larvae, the
pest becomes resistant to chemicals after
only a couple of days and around 80 per
cent of the eggs will survive. By contrast,
a population of 1 million bats will prevent
5 million larvae from hatching per night.
The cost of a single
pesticide application across an area of
4,000 hectares can reach US$ 100,000.
As well as the financial
costs, there are environmental risks to
applying pesticides. Pesticides can contaminate
groundwater and cause the loss of natural
enemies of bollworms, such as ants, beetles
and parasites, as well pollination services
by birds and bats. These potential losses
further increase the importance of bats
as a means of insect pest control.
Rodrigo Medellín,
co-author of the study and Ambassador of
the Year of the Bat said: "We must
strive to conserve bat habitats worldwide
for the sake of economic benefits alone.
In addition to their role as a pest control,
bats provide key services such as seed dispersal
and pollination of economically and ecologically
important plants. The educational initiative
of the Convention on the Conservation of
Migratory Species of Wild Animals is an
essential tool to convey this crucial message."
Notes to Editors
The Convention on the
Conservation of Migratory Species of Wild
Animals (UNEP/CMS) works for the conservation
of a wide array of endangered migratory
animals worldwide through the negotiation
and implementation of agreements and action
plans. CMS is a convention with special
importance due to its expertise in the field
of migratory species. At present, 116 countries
are parties to the Convention (www.cms.int)
Together with the Agreement
on the Conservation of Populations of European
Bats (EUROBATS) it has launched the Year
of the Bat 2011-2012. (www.yearofthebat.org)
EUROBATS aims to protect
all 53 species of bats identified in Europe,
through legislation, education, conservation
measures and international co-operation
with Agreement members and with countries
that have not yet joined. (www.eurobats.org).
